We're still not getting around the point that it's unlikely anyone will buy it in the first place...
I mean...how easily are you gunna sell a hoembrew game when the customer can go out and buy a pre-owned one for a fiver?
This is why Indie games are two things; cheap, and easy. Cheap because they work on the principle of micro-transactions, where one person pays £2, and thinks it to be a very small amount of money. So then they recommend it and it spreads across to 200 people. That's £400 for no effort. Indie games are all about word of mouth.
They have to be easy because that person's just paid for it, and they want it running
now. It has to be a small filesize, install quick, and run easily on their system.
FPSC does none of the above. You can buy Triple-A games that have smaller filesizes than an FPSC install.