I have shot a 300 with 60 with my hunting set up.... ONCE. but they were CE maxima selects, so not really a cheap arrow but a hunting arrow. They are heap compared to my indoor arrows though haha. I shot a 60 with my CE medalions with my field set up, good arrows, still kind of pricey, but very very cheap compared to guys shooting x10's and nanos for 300-400 a dozen....for just the shafts.
If you mean 300 fps out of a 60 lb bow, I shot 300 out of my Destroyer 340 with Gold Tip Velocity XT's. Total arrow weight with Blazer vanes and 100 gr tips was 385 gr. Max draw weight on my bow is supposed to be 60 but my buddy's bow scale says 61. I shoot a 30.5" draw length.
Have not shot 60x, have ended up with 294-298 and 52-56x shooting Easton ST Excel or Axis arrows. It's been a few years since that though.
Those same arrows would group less than 1" per 10 yards at 70-80 yards, although I would get one or two out of a dozen that would not. Helps to number your arrows so you can determine if a certain number arrow is the one that keeps shooting off.