While I can find resharpened carbide bits, those cheap, bench drill presses tend to have too much runout. They also run too slow for carbide. As a result carbide bits tend to break.
I prefer to use high speed steel bits. They don't break. They do wear quickly, but I can finish a typical board with just one bit. My preferred size is 1/32 (.032) inch as these tend to cost less than numbered bits. Places like Enco sell these at 65 cents a piece in lots of a dozen plus postage, of course.
Looking for a local, and lower cost supply, I looked to Harbor Freight. They sell a 30 piece drill bit set for $3.99. The set is metric sized, but very useful. Converted to inches the set includes five each of .020, .024, ,031; three size .039; and two each of .047, .059, .071, .079, .093 and 118.
For circuit board work, the 18 bits less than .040 size are a bargain at 22 cents each.
In keeping with the K7QO experimental mindset, I'll buy some tomorrow and report back.
bob-N7SUR