Donzi direct has them for $25.00 each. Wow!
has anyone found these elsewhere?
what makes them unique is the stainless cap but the light shines thru the tip too.

What switches in particular do you need boots for?

A link and or pic of what you are after would help. Some boats use a circuit breaker for the switch and it's not just a cap but part of the assembly and not easily changed.

Save your money these are available through Grainger or nearly any outlet that sells marine toggle switches. These are the larger boots located on the dash for your switches like engine hatch etc. found on the Zr correct? The smaller ones located on circuit breaker panels are also easy to replace. use a tiny bit of electrostatic grease on the threads when you reinstall. They are very easy to do yourself and keep them sealed up. I believe I paid like $2ea through Grainger a few years back.