Sounds like you already know it, but no dealer wants a trade in with 96K miles on it no matter how good the condition. They will offer you peanuts, about what they expect it would go for when sent to auction.
As far as what you will pay for your 06 GT, it totally depends on the dealer. Some dealers are still trying to get $5K over MSRP for GTs while other dealers are selling GTs for a few hundred $$ over invoice.