If you are planning to quilt as a business, you can obtain a sales tax permit and you will not (in the State of Texas anyway) be required to pay sales tax on your machine. I purchased a Gammill Vision 18/8 almost 3 years ago and love it. I have had a few issues and the customer service has been excellent. It came with a 4 year warranty on parts, but not labor. The techs are really good with staying on the phone with you and trying various things until the problem is solved. They don't want you to have to spend the dollars for labor either. If a new part is needed, they send it within 2 days and then walk you through the installation. I am feeling really comfortable with my machine and my abilities to problem solve now. My machine has a great stitch and I don't have any tension issues which I know can be a nightmare for some. I did not get many extras for my machine except for the casters and the batting bar on the frame both of which I'm glad I have. I live near San Antonio, but purchased my machine from Linda's Electric Quilters in McKinney, Texas which is about a 5 hour drive from me. When I was checking pricing, Gammill was offering specials and the dealers I checked with basically had the same deals. I would recommend that you take any classes offered which was included with my machine. It was 2 days and I had to stay in a hotel but it was well worth the expense. Good luck!

I really appreciate everyone's responses! I'm well on the way to making a decision. In a few more days I think I'll post some details about the specific machines I'm looking at to see if I can get some more guidance. I'm still in the information-collecting mode right now though. Without everything I've learned on this board over the past several months it would definitely be an overwhelming task!!

Dunster is correct on the sales tax issue--while you may not be charged SALES tax because you live in a state different from where you purchased the machine, you have a legal obligation to self-report any out-of-state purchases on your state income tax return and pay your state's USE tax. The USE tax is usually the same rate as the SALES tax, and is set up for these exact situations. Of course if you happen to live in a state without sales taxes this would not apply, but just because your state does not have an INCOME tax does not exempt you from the uSE tax. (I am a CPA).
As for discounts, I always try to negotiate for a little better price on big ticket items. Plus if you offer to pay cash or check they will often take off 5 percent which they would have paid in credit card exchange fees. Never hurts to ask!! Good luck!

At the big quilt shows, some of the companies sell their demonstrator machines at a discount which are only used at that show. Also, they have "show prices" for new ones. The HQ dealer in Michigan brought in a HQ instructor for 3 day of classes. Had "truckload" discounts - same as the show discount. He had my la delivered to my house and the drove over two hours to set it up for me.