Office of Steam Forum for Model & Toy Steam Gas & Hot Air Engines

Like Stoker said, for model work you are better off buying what you need individually.  When you start a project, buy the taps and dies listed for the build and after a few projects you won't need to buy any more.

The failure mode for a cheap tap is breaking-off in your work which could be catastrophic.  Buy the best taps you can and I recommend the 3 tap set as sometimes the bottoming tap is very handy. My good taps are either Greenfield Tap & Die (now Widia), Presto for BA or any other quality tap from an industrial supplier (not from a big box or hardware store).

For dies the best ones you can adjust with a screw. Accuracy aside, a cheaper die usually won't destroy your work.