Most expensive camera item?
The Fujifilm GF670 folder, plus accessories.
A reward for completing 2 years of tough software development skill set upgrades.
Call it about USD $2,000, or so, after shipping.

The best camera deal?
Any of the lost cameras I found while working at Disneyland many decades ago.
Took 'em to Lost and Found, waited six months, if unclaimed, they were mine!
An infinite return on investment.

Most expensive darkroom item?
A tie between the Hass Intellifaucet K250 and the Heiland TRD2/02 densitometer.
The K250 is easily the best single darkroom item I have ever purchased!
Each around USD $1,100 at the time, after all was said and done.

The best darkroom deal?
Probably the fully water-jacketed, 4-tank SS 8x10 Arkay sheet film processing line.
A little bit of Naval Jelly (phosphoric acid) clean-up and it looked brand new.
I'm currently converting it into a DIY gaseous burst system.
Original, pre-conversion cost was USD $85, as I recall.