I had an experience two dealers that were 50 miles apart. One dealer (again Caldera) was $1200 cheaper and included some throw-ins that the more expensive dealer was charging for.
The big difference was that the cheaper dealer was a two 'store' operation, was on a high traffic road in a fairly large city (the second store was also in a large city) . The more expensive dealer was in a much smaller town, delt with fireplaces, pools, pool tables and spas. So, by doing more sales one store was probably getting a break on cost and paying less per unit for shipping since they came in 12-14 at a time vs. maybe 1-2 at a time.
There was no way the more expensive dealer could match the cheaper dealers price.
Another thing to consider. If you buy your spa 2 hours 'up the road' do you suppose the local dealer will be eager to come to your place to do warrenty service work? Or after warrenty service work? Your local dealer will do work on your spa, but you may be at the bottom of the 'to do' list.