A. BUDGET SOLUTION.
Buy a set by BST. (that's what is says on the box, sadly I have not found it on the web, maybe you'll see it displayed somewhere...).
B. QUALITY SOLUTION.
One of the best brands out there is Gühring.
German made, and apearantly, also available in the US
(http://www.guhring.com/AboutUs/Distributor.aspx).
1. The startersets in supermarkets, DIY-stores and stuff, are usually ****.
2. If available, buy "machine-taps". You only need 1 tap instead of 3. And they are usually of better quality.
3. If available buy taps for blind holes (they are flat at the end and makes it possible to thread blind holes, but can also tap normal holes).
A small starterset has: M3,4,5,6,8,10,12
A bigger starterset has: M3,4,5,6,8,10,12,14,16,18,20
When you have those, you're pretty much equipped.
Price of taps is highly dependent on the material it is made to cut.
I don't know the prices in the US, but here a good quality (machine)tap costs somewhere between €15 and €50 (real exotic ones go up to €300).
Dies are about the same.
Happy hunting !
