Bear in mind that when you trade-in a unit, your sales tax on the transaction is based on the trade difference, and not on the full purchase price of the new unit, so that in itself narrows the gap a bit.
I'm making the assumption that the $14,000 trade allowance is a net figure based on a discounted price on the new TT, and not an allowance to be deducted from the MSRP of the new TT.
I'd just use it as a negotiation tool. Take your offer from CW, in writing, with you to the dealer(s) you're trying to buy from. Then, make them a legitimate offer. Be ready to buy. Don't be wishy-washy. Tell them, for example, "if you give me $15,000 rather than $14,000 for my trade I will give you a deposit and sign the paperwork right now".