So I have been told by my employer that one of the tools I will need to add to my bag is fisheye lens.
Ask him "why" not to challenge him but explain that there are several fisheye lenses and which one you should get depends on the subject and the desired effect
The first fisheyes were designed by Nikon for doing tank inspections. The idea was you'd lower the camera into some access port and get like a 270 degree view of the inside of the tank. Others were made for arial mapping. Only later did people try them for general photography.
Fish eyes do not render straight lines straight but distort everything. It is a very specialized lens and the effect is so pronounced that it "gets old" quickly and you have to use it sparingly
It could be he is confused and has misused the word "fisheye" and really meant just "extra super wide". Not everyone uses technical terms correctly. So ask "why".
I'm betting he meant "ultra wide".
Does he really like the distortion effect? If so could it be added later in Photoshop? Or does he just like the "in your face" wide angle style that is the current fad.
True circular field fisheyes are "way expensive". but a zoom that goes to 10mm is only moderately expensive and good to have.
Sounds like this might be tax deductable. If so you'll get an effective discount
but it just seems rather expensive at £500+
Yikes. Buy a plane ticket to New York. Buy the lens there for $570 (B&H Photo) and have a lens AND a short vacation for the price of the lens in the UK.