...what should I expect to pay for grapes vs crushed grape buckets
Ahhh, that's the annual question/debate for those of us not close to either coast (where they are grown or shipped).
Prices vary depending on the varietal, the quality of the crop/production volume, the supplier quality, and the freight distance, but locally I have gotten fresh California grapes (very good quality, supplied by F. Colavita and Son) for ~$50-65 for red grapes from Cabernet Franc, Zinfandel, and Shiraz on the cheap end to Petite Verdot,Cabernet Sauvignon, and Malbec on the high end (usually).
I'm not sure what's included in 'crushed grape buckets,' I think that is something offered in the northeast as a simpler way to distribute fresh juice (instead of as fresh grapes). Whether that is 'better' or not is a matter of opinion - I don't think you need the crusher/de-stemmer for those buckets those.
From Fine Vine Wines in Dallas where I get my grapes, they strive to get enough home winemakers to make freight a reasonable expense - trucking the fresh grapes from California to Texas is not cheap. Once you get over a certain volume (as small commercial wineries will just reach), it makes more cost-effective to order the grapes directly rather than go through a 'broker' such as your LHBS. So for those of us ordering 3-15 lugs, it is difficult to find a LHBS that will collect the orders, consolidate them into one big order and handle the shipping, delivery and distribution of those grapes. I am told few LHBS make that effort each year, like FVW does in Dallas.