Good for you man. That's great, but the default in 5e is much to quick, so milestone is a more efficient way to emulate old school without house ruling in the old XP charts and at that point, just buy the 1e books off DM's Guild.I can't think of anything more antithetical to old school play than milestone leveling. Even the alternative you suggest misses the point. XP for recovered gold does the thing it is supposed to: focus play on results (recovering that treasure) not process (killing monsters). The XP is hidden behind a secret door, or trapped, or in the monster's lair. How are you bunch of crazy fools going to not only get it, but get it out and back to town safely?