No, you're not overcharging. That's an okay starting rate for a location map. For a map someone's putting in a published book, I'd say they're either new to it or trying to exploit you not knowing better.

You CAN do cheap commissions, if you want. You'll burn out in the end because people will want more more more without respect to what you charged. It's easier to find ONE person who'll pay you $500 than it is to find 20 people to pay you $25. Yes, there are people with $25 budgets desperately trying to scrape by and it's okay to think of their needs. However, they tend to be some of the worst and neediest clients, so, someone who tells you they can't afford $50 is probably you dodging a bullet. The reason for this is not that they're poor, it's because they have very little experience working with a commissioner and they don't know how to work with you well. Someone with a big budget might have expectations but they will also have experience.

I have a vague pricelist, I'm very flexible depending on timeline and the density of the map in question, but I almost never go under $100 these days, my lowest end maps are $75, and if you can't pay that, cool, I have free map stamps and a tutorial and I will answer any questions you have about how to make your own map from the myriads of stock resources.

How do I make my prices?

I know approximately how long it takes me to draw a map. So, I have an hourly wage that is no less than minimum wage for a project, but usually $35 an hour if someone were to ask what I'm basing it on. I also add a few hours at minimum wage to my quote for the work that went into talking to the client via emails and fishing for the clients... that's why I no longer do cheap maps, because by default I'm budgeting in around $30 towards "not actually drawing but the work that's required to get a commission". I also add up the cost of my supplies for the year and divide it up by 365 and include about 1-4 weeks of "what it costs for me to have an appropriate setup to do this art". For the record, I spent around $2000 last year on various things to support my work, so, it costs me about $5 a day to have what I need to perform art at the level I'm doing now. If I work for someone for a week, $35 goes into related costs. Now, last year I did buy some unusually expensive work related things, but nonetheless, say you have an Adobe subscription, well, you need to factor that into your wage.

So, you see, for one map alone, I'm looking at at least $60 of tangential fees that are not just "I'm drawing the map and charging you precisely for that time". That's some of why I don't usually charge hourly, and if I do, that's why I base my rate on something that's more than double minimum wage. Because there are costs associated with having the equipment and lifestyle to be able to draw maps ALL THE TIME!

If someone were to ask me for a quote right now, for my most common product, which is a mid-sized continent or country, I'd give them a quote between $100-$250 (depending on how dense it was) and if they asked for a poster, they'd get a quote of $300-$800, depending on how rendered and detailed it is. This will weed out 2/3s of people that I contact based on a job, or who cold call me out of curiosity (those people I include the note "my prices are negotiable if you are a non-professional looking for a map for your private game"... because that's true, I will gouge my prices significantly for someone who wants a personal game room piece rather than a publication piece). My lowest cost product is a black and white novel page sized map, for which I charge $75 USD per page (or $150 for the two page spread). It does take me more time than 2-3 hours to create such a map (if there weren't a back and forth I could do it in a workday), but indi authors aren't making huge banks, so I've always endeavoured to keep that particular map style low cost compared to high end full color posters, which I'd rather do a selective amount for a specific handful of clients rather than enduring gruelling hours.

Note: my low end product is still more than you feel uncomfortable charging. 80% of the time I regret taking low 2 digit commissions. With one exception recently, a teenager commissioned me to do a map for her GM, she was very nice, and I gave her a very good deal, that commission rolled out smoothly. I just had a good feeling about it so I accepted it. Trust your gut. Your gut knows if a client's giving off red flags.

It is ALWAYS easier to find one client with a high budget than several with a low budget. It will ALWAYS be a better experience. If you want to do low cost work to help people with small budgets, make stock art packs available on the DMs Guild or whatever. Don't let someone with a stock art sized budget push you to do extremely custom artwork. It will burn you out. If you want to make generic stock, do it on your own terms and advertise the packs to those people who say "ah, that's too much".

My solution for those people was to make a list of all the free fantasy map tools I could find on the internet. You don't have a budget to hire me? That's fine. I have a reason for charging what I do, but I don't want you to not have a map. I just don't want to do it, because I will ultimately make more money over the long term if I spend that time not on a $30 map pack, but on a kit of Roll20 tokens that resell repeatedly over the course of a year. If you only have $30, get Wonderdraft, get Other World Mapper, get Dungeon Forge, it's super easy to make your own map with a mapping specific tool and I encourage it to all low budget indi creators.

It isn't just for my sake, too. It's also for them. If they lowball, they're not going to get the best possible art for their creation, and visuals are what sell RPG modules and game sets. And if they try making maps they might realize why our rates are like this, or discover they love making maps! So that's not a bad thing. I'm always happy if the outcome is "and the cheapskate client woke up to the joy of cartography and now they make dungeon maps every day."

Why should you listen to me when my profile isn't full of little Cartography awards? Eh, I dunno, maybe because I'm successfully making my living as a freelance fantasy cartographer almost exclusively and have been doing this professionally for 7 years. I have a good idea of why it's worth charging more money than you might think you're worth, because I used to do it wrong and burned myself out on $35 maps, leaving a wake of disappointed clients whose needs I could not meet when I surged in popularity and could not actually keep up.