The manufacturer to dealer or dealer to dealer transfer is not something that you pay for.
If you buy something from an out of state dealer, that dealer will need to transfer the item to your local dealer. This takes some time, but not nearly as long as when transfering it to an individual. When your local dealer gets it, then you start your paperwork.
You could save a few weeks time if you can find a local dealer that actually has what you want in stock.
One of the big things about buying this stuff is finding ANYONE that actually has one. This is a guess, but I don't think that most of these suppressor companies are real big manufacturering concerns. I think that they make a production run of suppressor X, then a run of suppressor Y etc. If you decide to buy an item that they arn't going to produce for awhile, good luck finding one. I have waited longer for the suppressor to be made several times than the wait on the tax stamp from ATF.
Check the boards like AR15.com equipment exchange, NFA section. Dealers advertise suppressors and other NFA items that they have in stock. If you find someone that has what you want, you are in business.
Let me caution you on one thing. Don't get in a hurry. Don't get all caught up in the time involved. Don't buy something you don't really want just because you can get it right now. The NFA weapon game is a waiting game. Take your time. Shop around. Don't pay retail for nothin. If you are going to have to wait two months to get the stamp, why not wait three or four to get exactly what you really want. There isn't a big used suppressor market. Pretty much count on having whatever you buy for the rest of your life.