what you might do is talk to the dealer of the new boat and find out if they are planing on showing it at any of the in water boat shows in the area. if they know you might be serious about the new boat they might invite you to go on the delivery for the show or a demo sail.
which dealers are you talking to?
does the dealer know you have a boat?
it is a buyers market right now and he may just need to be worn down a bit before he will get you on a Demo sail.
In Southern Califonia there is very little space for boats to be on the hard and it will cost more then keeping it in a slip
so most of the new boats here are in the water and a demo sail is not that hard for them to do.
Another way to get that sail is if your wife asks more questions then you do about the boats performance under sail and how it handles different sea states.
another way is to charter or take a lesson on one of the same model boats that you are looking at. that way you are paying and can sail it the way you want.
"FULL TILT II" 2011 BENETEAU FIRST 30
"FULL TILT" SOVEREL 33
"GOLD RUSH" PRINDLE 16