I have one and use it sometimes on my Kiev-80, which is the same camera as a Kiev-88 in almost every respect. I had to do a little custom metal removal with a file on the mounting flange of the prism finder to make it fit. It works, although I generally prefer the image quality of the standard waist level finder. The only real complaint I have for the waist level finder is its laterally reversed image.
I'm usually fine with waist level viewfinders (used Yashica Mat and Rolleiflex TLRs for a while now), just wanted to explore the options and I reckon a 45 degree finder would work quite well on a medium format SLR. Anyone else have any opinions on them? Price checking is difficult, they don't seem to sell many of the original or clones.
They should be, but they seem to be cheaper in the US market than in the UK market (as with so many things, sadly).
I'm quite tempted to instead pick up the TTL/Spot metering prism from Kiev, the latest ones are made to work with 3 LR44/AG13 batteries and it would be nice to have a TTL meter (I have a handheld Sekonic but it does slow down things a bit).