Outrageous overbill by Kanter Automotive

you're not going to like what I think as a professional parts guy.
132% is too low. The number should be somewhere around 166%. That is an industry standard. that # pays bills and allows for a small margin of profit.
keep in mind, that it is not reasonable to expect that you could have gotten the job done cheaper. discounts are given to volume customers. he also bears the burden of warranty of your part and has to live with it if/when it comes back.

I also would have had a chat with who ever shipped your part. I would have done some creative billing since the cat was out of the bag.
Actually the industry standard mark up is cost X 1.66 which in this case
Kanter should have charged $243.09 giving him a 40% gross profit. Kanter
roughly market it up cost X 2.32 giving him a 62% gross profit. That's
usually impossible to get on big ticket items, mostly little crap like nuts & bolts and heater hose we can get away with.