Well taking a look the prices seem ok to me but that is very dependent on the quality.. What would you expect to pay for a M6 x1 spiral flute Tin coated?.. decent quality branded taps can be pretty pricey but worth the spend. The last thing you want is tapping holes as the last op of a job and get broken taps. If the quality is good then i think the prices are fair. Generally the quality from apt is fair to good and not uncommonly exceptional, good value for money overall. I use a fair amount of their tools on commercial work on my Vmc's and they fair well for the price.

What exactly are you machining and the materials?