Totally Screwed Machine Shop
Drills for the beginner
I am no expert on drills. I have been buying them to meet my needs for several years, on the cheap. If you can pop the spendollies for a cobalt 115 pc set for ~ 400$ you probably will be wasting your time reading further.
There is no secret. You generally get what you pay for in drills. To my mind the question has been "do I buy full sets of high quality drills" or "do I buy cheap, nearly worthless sets". Having any drill that meets the needs is a heck of a lot better than chucking something in the lathe, dialing it in and boring the hole, starting the bore without a drill is irksome at best. If you think you'd enjoy boring all your holes..There is great news in that you only need a couple drills to get you started.
Drills by the very nature are not incredibly accurate. My thought is that if you are drilling you have a margin of error. So the quality of the drills is not a real issue as far as accuracy, or you'd be drilling under size and reaming.
A cheap drill does not last in machine usage as long as a good cobalt drill (not nearly as long!), but it costs only a fraction of the price. When chucked in a hand drill motor they get closer to even, with maybe HSS (High Speed Steel) being the bargain. So the quality of the drill has a very real bearing in life expectancy.
If you need a drill but don't have it you are so screwed! So quality of drills have a real point in availability. Hmm maybe I'll need to correct that to the Price of drills has a real point in availability, however the 1st premise gwypf (Get What You Pay For) leaves it accurate. :-) Along the lines of availability one can kip off to the local hardware store and pick up fractional sizes in the US and metrics in other countries. Likely not alphabet nor # sizes though.
In the back is a 115 pc set of HF tin coated drills that I have had for a decade. A handful of drills have been replaced with better quality, but mostly I drill a pilot and run these down the hole.
I think a really good setup for the beginning machinist is to populate one of these index. Drills for NF, NC, taps and clearance drills down the middle.
If you run across one of these cabinets at a garage sale...BUY IT. If they have 2 buy both. you need more of the smaller drills and this holds ALL of them well.
Drills are a tool. you need what you need until you need something else. This makes us opine that we need every drill we can swing. T'aint so. Sacraligious as it is buy what you need. In this case buy twice isn't so bad, but filing a 7/16" to 1/2" wouldn't be pleasant.
Nobody wants to pay shipping for a drill, nor does a hobby machinist want to buy a whole pack of drills so good indexes start looking better if you live in a remote area. Usually I'll sneak a couple drills in with every order from MSC, McMaster etc. Sometimes I can pick up decent singles from Fastenal but all to often now they want you to buy a pack. Grainger is usually my go to place for replacement drills. Order online, will call, and pick up local with no shipping!
These are my opinions, and may have little bearing on your experience.