I really haven't looked into the bulk stuff. A lot of varieties aren't worth submitting even in MS65 and I never really have a whole pile of 66 coins of the same variety. But I suppose it would be worth thinking about, since the reduced cost could actually make those 65's cost effective to submit. The math works this way for varieties. If you submit one regular coin it comes out to be about $98 after grading fees, form fee and shipping. Submit a bunch and you can get it down to about $60/coin by watering down the fees/coin ratio.
ebay fees are 10% and other auction houses even more, so selling the coin for $70 is the bare minimum break even point. But...if you could have just sold the thing for $25 RAW, well then you are losing money unless the graded coin sells for at least $95. Given that it is pointless and time-consuming to break even, in general a coin should have a resale value of about $125 before it's even worth the time and trouble. And all that assumes you have almost nothing in the coin to start with.
Lots of folks would like to have their better coins in a PCGS slab, but overall the cost is very high. Submit 20 variety coins and you will pay a bill of $1,200 for the service. That's a lot of money going away. My annual grading fees come in over $10,000, and I would love to not have to put that kind of money in the PCGS pocket as it just runs the price of everything up. But at some point the expensive stuff is just worth a lot more after it's graded since buyers know it's a solid coin and not cleaned or damaged.
All that said, ANACS is a great company and does a whole lot better with varieties for a whole lot less money. Their slabs don't bring in the top dollar on the back end, but it's less than half the money up front. With them I do have a bulk agreement and submit large numbers of variety coins at once for a better price. It takes them 4 months to get the coins done, but it's always rather a good day when that box arrives. That project is actually on my list this week, as it takes a couple hours to put that whole submission together.
Best of luck