My local bicycle group bought very nice but very expensive torque wrenches (if I can remember right they cost about €300–500). My local discount store markets them for about €50. My local auction site has them ranging from a few euros to many hundred euros.
I don't care about product recommendations. I want to know how I can objectively evaluate them. I know that even a superb one can deteriorate due to poor handling, hence my local bike group locks them. It must always be unloaded to 0 Nm after use so that the spring won't deteriorate, non-verified information. I am planning to invest in one because I tend to destroy the metallic things such as these here. If not at all possible, please let me know whether I could use any hardware store tool for bicycle things or should I invest in one marketed to bicyclists?
P.S. by torque wrench I mean the thing that shows Newton meter units.