Wet test and if you like that spa, negotiate the best price you can and go forward from there. If the dealer lets you walk vs making a sale, you know that you're hitting their price.
Prices vary too much across the country for anyone to validate your price. In general it seems most premium spas come in at $7K plus- so your price seems to be in the general ball park.
Most quotes include a cover, steps, startup chems, and delivery. Does your price include those? Also get a cover lifter if one isn't part of your package.
The only other suggestion would be to get price quotes on similar spas from other brands, and compare that way. But if you may not have that option if you live so far away from spa dealers.