If I go to my local coin store, the majority of proof nickels are probably between 2-5 dollars, depending on the year.
The 1979 and 81 type ll proofs probably cost a little more.
If purchasing from
ebay, I think the lowest I've paid for proof nickels is around 2.50.
I had purchased graded 1970-S that was only like 10 bucks awhile back.