What has been the most you ever paid for a calculator?

[Xorand]

A tie between the first and last new calculators I've purchased - US $150.

1976 - Texas Instruments SR-51A
2017 - HP Prime

I no longer have the original TI, but recently found a pristine one on eBay, restored the battery pack and it works great.

I kept the Prime for a year or two but sold it. I just couldn't read the orange lettering on the thing, so it was fairly annoying to use. It felt like cheating writing stuff in the emulator on my PC and downloading it to the device.