Outer Limits 4x4 Board

I have been on the hunt for a thermostat for a TB45 engine. Mr Nissan wants $58. Autoparts shops want $66-85. Why is this thermostat so expensive? Some auto shops said they have never sold one and dont have it on their system.
I went digging in the Tridon catalog and found that the RB30 thermostat was the same size and temp but it has a bypass valve. Can I just cut off the bypass valve? I can buy the RB30 one in supercheap auto for $22.

This one is the TB45


This one is the RB30

Got mine from the nissan dealer 3 weeks ago for $44. Shop around.

I would be worried about corrosion. When I chopped my old one up it looked like brass coated steel or something.

I would spend the extra $30 odd $$