Back to the OP question..
Never settle for the offer they gave you.. always ask for more.. Especially when paying cash. The lift is $250 to $300, so if you get it included, that is the approximate discount. Steps are overrated in my opinion, I built mine with composite decking material for about $40. The gfci box is an expense that the HS throws in. The HS box does indeed have a slot for a 110v breaker, although it is not in there when you get it. This allows for adding lighting without having to run additional wiring.. most lighting does not draw enough to be a problem with overall current draw on the circuit, or imbalancing the legs.
I look at it this way: The spa dealer is always going to shoot you a price that has a little room to come down. It is like buying a new car.. there is a lot of competition and they know they will have to make their deal as sweet or sweeter than the competitors if they want the sale.. I cannot imagine a spa dealer that has so much business that he will not be willing to deal.. if that is the case then you are probably better off with his competitor.
Ask both of them to sharpen the pencil a little, THEN if you decide on the Sundance, AFTER they sharpen the pencil, offer cash/check and get them to throw in some added value, or reduce the price further. If they won't go down and you still want that tub, pull out the credit card and remind them that it costs them an extra 2-3% if you charge it.. it only makes sense to them to give you something or reduce the price by a hundred or two.. Everyone pays credit card fees.
If you really want to get the best price, don't be afraid to walk out if they won't deal. Once again, unless they have so much business they really don't need your sale, watching a $7k sale walk out the door will make any salesman reconsider.
Oh by the way, for a 3% increase in the cost of the product, adding ozone is, in my opinion, a smart buy.. worst case scenario your water is a little cleaner.. I look at it this way: Ozone does sanitize water, its just a matter of how well it does it in a spa.. so at the very worst, you are sanitizing a little. BTW, I go sometimes 2 weeks without using my tub in the summer and if the water was clean to start with, it is clean after 2 weeks of no chems.. I use a HS with ozone and silver ion.