Wow, thanks everyone for the positive recommendations!
Despite being the owner of a picture frame company I have never hand cut a mat other than in a framing class. When I was first starting Frame Destination I bought pre-cut until we had the revenue to get computerized mat cutters. I would rather be out taking pictures than cutting mats. Of course there are advantages to hand cutting mats, but if you are able to buy at qty 25 there is very little if any savings over cutting yourself.
Regardless, my company along with many others can sell full-sheets or pre-cuts. If you do decide to go the full-sheet route and you are reselling you might see if you have a frame distributor in your neighborhood that can help you save shipping cost. If not our company can at least spare you some shipping damage since we do not pack full-sheets the way most companies do.