I've had decent success feeding the Moab stock into a 3880 (about ten sheets at a time in the rear feeder), but I'm having two problems with that. The big problem is that the Moab paper is extremely expensive, and I can't sell the cards for enough to really make it worthwhile (especially wholesale). I'm also moving to a 7900, and I CERTAINLY can't sell the cards for enough to make it worth dropping them into a 7900 one at a time. My present thought is to run cards on roll paper (anything thick enough, much of which is MUCH cheaper than pre-scored Entrada), then get a print shop to cut and score them on their big equipment (in batches of, say, 250). Of course, if I had to run off a small batch, I'd trim them on a Rotatrim and score them on a straightedge.
I had also wondered about two other ideas. One is a dedicated card printer - something with only an 8" carriage, but a robust paper feed that would take more than 10 cards at a time. I haven't been able to locate anything that has more than 4 colors (it doesn't need to be 11, but I'd like to use at least a 6 color printer) with a serious paper feed and decent-sized cartridges. Someone mentioned a few particular lasers that had decent color on another thread, and a laser would be attractive because it uses much more reasonably priced stock. Of course, I could also cut the stock cost by using Red River instead of Moab, but I've never seen a sample of the Red River stock, and it's an online-only item with a single source (Red River directly) - I have occasionally picked up the Moab locally if I need a few extras, and there are multiple online sources, which is nice if someone is out of stock.
The second is having someone else print the cards (on an Indigo or some other big digital press). Every source of this type of printing I've found gives price breaks based on quantity of the SAME IMAGE. The problem is that, while I may print 250 or even 500 cards at a time, I sell assortments, so I would do 10 each of 25 designs. Most print shops count that as 25 orders of 10 cards (although, with an Indigo, which is just a super-size inkjet, it actually doesn't matter, and they COULD price it as one order of 250 cards, because the cutter and other setup is the same). If anyone knows of a good print shop that takes advantage of the flexibility of the digital press in their pricing, I'd love to know about it.