I'd stay away from 52100 if I were you. After heat treatment it is so very abrasion resistant that grinding it becomes a real drag.
If you don't have a good belt grinder with ceramic belts, 52100 is not a good steel to work with.
and even if you have, for a razor it is really no better than O1.

But indeed, if you got a dozen blanks for 50$, that's a good deal especially.