I am starting a thread that I will resurrect anytime I come across something interesting. Please share any rpgs you would like as well. My original thought was to create a list of good rpgs and under $10, but you can always just share something amazing and I will wait to see if it goes on sale.
The first two I mentioned in a previous thread, but I will be adding more as I find them.
Legend - core rulebook $1
After Mongoose lost their Runequest license, they stripped out the few mentions of Glorantha in their Runequest II books and re-released it as the unfortunately very generic and easily overlooked title Legend. The main change between the two books is the fluff character creation story to teach the reader how each step works.
The system is 100% the same and it is my favorite d100 system. For $1 its a steal. What I love about it, character creation and improvement systems as well as the combat maneuvers system which has the potential of a defender being able to turn the tables on an attacker by blinding them or tripping them, etc.
Dragon Warriors - pay what you want
Old school game original released in the 80s. This version contains errata from the previous 2009 Mongoose version. I have never played it and some of the magic systems seem clunky, but overall its pretty neat. I like their defense system. It seems different enough from D&D to give it a go.
Nanoworld - Free
The PbtA game that taught me the system and how run a game with no prep. Great for one shots. All players are clones, the group creates what the clones are in character gen and the game starts as something goes wrong. It would be neigh impossible to run the same game twice. So much game in such a little package, its a 6 page pdf and 3 of those pages are images. You use to be able to send Marshall a $1 and he would mail you a business card with all the rules printed on it, but that was years ago.