Hate to do it

If you can't find an 8 1/4" for an a body for under $300, it seems like you're not looking very hard.

Upshot: sure grip stuff is cheap n easy, and it's a bolt in.

If you're relocating springs, damn near ANY rear is going to need it, so that's a wash.

What are your plans for the car? What issues are you anticipating? I bought a complete 8 3/4 sure grip drum to drum for $300, and the bbp axles left me under the Mark you're quoting and it was ready to run.