When to trade? Easy. Never. Sell it first then buy whatever you want. Trading is a losing deal every time.
It depends. You in NH don't have the sales tax issues in play. In a state like mine where the sales tax is between 7% and 9.75% depending on the value of the vehicle, and where they do not charge you sales tax on the value of your trade, trading can be financially just fine.
Also, if you are trading a late model low mileage bike, trade values can be high if you're good at trading.
I've traded two bikes toward one. I've traded high dollar bike toward lower dollar bike and gotten cash back. I've traded low dollar bikes on high dollar bikes.
The key to trading is to be realistic. Make sure they know that you can do the deal without the trade. That way they figure its worth their time to keep working with you. At the same time, focus on the cash difference as opposed to the value of the new bike or the value of the trade bike.
A nearly fool proof final line is "Well, I'd do it for $X, but if you want to do it for $(X + 400), I'm going to have to run it by the wife." The usual response to this is "We're so close, and I don't want to lose you over $400, so I'll do it for $X. You've got to be talking to the sales manager to get this to work, but you should be talking to the sales manager anyway.
Trading is a lot of fun. And you don't have to put up with the Looky Lous, you don't have to put up with test rides, and you don't have to fool with guys who may or may not get approved for the loan they'll need.
I never sell bikes outright unless they're ones that have lost their trade value. Older bikes, high mileage bikes, salvage title bikes, cosmetically ugly bikes.... prepare to take a bath on any of these, if you can get someone to take them in trade at all.
