Just curious: what are you using it for?
I bought a couple of very cheap digital torque transducers and had them calibrated (not on my dime, it was for work). They were very accurate out of the box. I would not hesitate to build an engine with one of those.
i would also add that in many cases the true torque is not as important as having all bolts torqued to similar values (within reason). Have a repeatable torque wrench will accomplish this.
Digital Torque Adaptor | Princess Auto