Prices vary greatly, but if you talk to anyone who has just lost a raccoon, woodchuck or armadillo in a poorly made trap, if they had it to do over they won't go cheap again.
Jim is correct, but he left out there is a lot more that needs to be considered. That is the ability of the trap to have a reduced magnetic field. The lower the projected EMF going over or through a trap or trap device the more total animals will be caught with less refusals. Two traps or trap devices can look similar and even look to be the same but are not. The trap or device may be sold as a Best trap for red fox and Bobcat but when tested shows that it will not prove to be that way. The test doesn't lie. It is accurate. What works best for one animal may not be for all. You can have the best functioning trap in the world but if the animal will not enter, how good is it. If you can buy a cheap trap that will catch baited sets (better than trap that does not test well) and that is the only sets you use, it might be better to buy that cheap trap. If you need a trap for forced sets or positive sets it may not matter as much unless your animal is educated and older, then it goes around or forces himself through a new hole he makes. There are powered door cage traps that will work for all, you just have to find and stick to those. It s the same for other trap/devices. At least a 4 t0 1 catch ratio difference and shorter time frame to eliminate the problem being very important in ADC work.
Any one that disputes that after what can now be tested is mistaken. He either does not know how to test, has not done the testing, or is telling a yarn to promote sales before it is common knowledge. EMF testing of devices will cause some devices to be more limited to more targeted animal species. They could be snares, conibears, footholds, or cage traps.
At least this is what I have found to be true. EMF test your traps to know what ability it has for the animals targeted.