Option 1 This is tough to beat price for a Whole Gaming System - The Drive Thru Vaults & Vows Bundle https://www.drivethrurpg.com/product/440205/Vaults--Vows--Bonus-Printed--Digital-BUNDLE
with little work you can run Dungeon World Modules to this as well as Iron Sworn. Can always just run Valuts & Vows https://www.reddit.com/r/Solo_Roleplaying/comments/15hi4z6/i_smashed_ironsworn_and_dungeon_world_togetherits/
get https://www.drivethrurpg.com/product/360541/Quest-Fronts--Issue-1?src=hottest_filtered
Option 2 - *just a disclaimer - people seem to have a hard time understanding the magic system. I think it is simple and fun to use.
Black Sword Hack Ultimate Chaos Edition - yes the book has to come from Europe and will take it’s sweet time getting to a US address. Everything is basicaly in this one book.
https://www.themerrymushmen.com/product/black-sword-hack-ultimate-chaos-edition/
Option #3 *players may be relunctant to play due to notorious rep of creator. This is one of the best playing OSR Games out there. Remove Venger and this would be Number 1 OSR Game. Did I mention it is FREE
https://www.drivethrurpg.com/product/303380/Crimson-Dragon-Slayer-D20-Revised
honorable mentions OSE, Cairn 2e, Weird North, Electric Bastionland, Mausritter, and Ruby