I was going to say earlier in the thread that the cheapest deal isn't always the best value one, a good dealer will offer first rate back up service, they will be accommodating when you come to upgrade (with easy and fair trade in deals) and of course they're accommodating with trials and demonstrations, they will find you the best solution for you even if it's not the most lucrative for them.
The dealer here has certainly got the trial/demonstration part right and trusts customers to try kit at home, that's usually a good sign and I'd be inclined to shake on the deal.