RageAgainstNate

I'm looking to purchase a 87 pickup this week, but the seller just informed me that the lock outs and making noise when you lock in the 4wd. Now my thinking from what the sellers has told me about his driving is the the bearings are dried out due to lack of use(he completely redid the body and doesn't drive in the winter). But of course worst case scenario is that the wheel bearings are shot. Now my question is, what kind of repair cost would I be looking at? I just need a $$$ figure to work on the price a little from the seller.

Thanks
RAN