Fuller bits & plug cutters
Bean an ole woodworker it's hard to imagine a toolkit without the Fuller taper drill bit and counterbores and a set of plug cutters. There are NO substitutes. And Fuller is a family run business - which are disappearing like rare ducks these days - so we should be supportring them anyway.
Fuller kits at www.ehartwicks.com (just for example, have not studied their prices, but they do have helpful intros to the Fuller 'system') start at $80. That puts you in business for drilling traditional screw holes.
You need to check the size of the counterbores - different screw sizes share the same size plug hole maker. You will most likely need 1/4, 3/8, 1/2" - TAPER plug makers.
You will then find you have to have size 14 for 1/4" screws. Not sure of the plug cutter you need these days for that size. 5/8"?... but that's a good size to have for burying carriage bolts, say. Or erasing a bad hole scar.
They may seem esoteric at this point - and you will never need them all the time. But when you need them, you can't do it right without them.
{There are probably size 8 and 10 screws used mostly in the A/C. And those two might share the same plug cutter - so you could get started with 3 pieces and expand as you require. It would seem that some intelligent merchandiser would put a basic kit together, like in a nice wood box, that would INCLUDE the plug cutters that go with the taper/counterbores. At a decent price - but that is asking too much.}