Not that it can't be done, and I don't want to dampen your enthusiasm, but if you want to sell a game, you need to understand the reality of the computer game business.
I was an indie game developer for 10 years. Out of those 10 years, only 1 year generated any profits for me ... and it wasn't much. In 6 of the 10 years, I barely broke even (meaning the business paid its own expenses, and that was all), and 3 years were losses for me. Those 9 years tell the same story as probably 95% of indie game developers.
When you run a business, particularly an online one where your customers download digital products (e.g., games), you need a good web host with decent bandwidth and reliable up-time. You also need a decent computer - preferably several with different configurations and operating systems representative of the kinds of computers your customers are likely to be running (although it's a bit easier nowadays with good virtualization software to set up a single computer with multiple virtual machines on it). Only after those up-front expenses, plus paying the monthly web hosting fees, merchant fees, high-speed internet fees, advertising fees, etc, plus paying for high quality graphic/audio expenses for the games you make (to ensure they even have a chance to sell) - only after all of that, can you pocket any money for yourself.
I was one of the lucky few whose first game was a "hit". That is not the norm. My game was featured in the Independent Games Festival, a couple of national magazines, lots of shareware sites (which were still pretty big back then), tons of game review sites, and a number of other places. Plus it generated a good base of loyal customers that helped spread the word over social media and drive traffic to my site. Even with all of that going for me, I still didn't make any money. Why not? Because there's a vast difference between making a good game (which in itself is difficult to do) and selling a good game.
The PC game market is over-saturated with games and has been for many years now. The internet has made it easy for any Tom, Dick, or Harry to make a game and post it online with a price tag on it. Unfortunately, that same internet has made it extremely difficult to get noticed amongst all the noise. That's the problem I experienced, and many indie game developers would affirm it.
Even in a niche field like RPG Maker games, it can be tough to get noticed. Look at Amaranth's site or Aldorlea's site, and you'll see there are already hundreds of commercial games available that were made from RPG Maker. There are also hundreds, if not thousands, of free games that were made from RPG Maker. If you want to sell such a game, and make money doing it, it needs to be something truly special to stand out. You need to be very good at writing and crafting a compelling story with memorable characters. You need good mapping skills, and your maps need to look amazing. You need to spend a lot of time balancing out the game, in terms of pacing, experience curves, rewards vs challenge/difficulty, etc - if it isn't nearly perfect, players will notice. You probably need to use some custom graphics, sounds, and music (which will probably cost you), because with so many games already available, players want something new and different.
Amaranth and Aldorlea have proven that you can earn a living from RPG Maker games. But I'm sure they will be the first to tell you that they've had to work really hard to get where they are, and they've probably caught some lucky (and rare) breaks along the way. It didn't happen overnight.