In terms of weight, most times, you won't NEED to fill your fresh water tank. We never fill ours at home because our fresh water tank is at the very front of our trailer and would put a LOT of weight on the tongue. When dry camping we use a water bladder that we fill and haul in the back of my SUV after the trailer is unhitched in camp. Then we use an old water pump to transfer its contents into my fresh water tank.
You may need to not bring the canoe, or maybe you can figure out a way to put it inside the trailer when you're traveling....? Any heavy gear that you can take out of the car and securely put in the rear of the trailer will help with that tongue weight.
As for getting a good price...you may need to wait a bit. This is still prime time for camping. Folks who are planning on selling will tend to wait until they're had their fun and the season is over before listing their trailer.
Also, expand your purchase horizons. We're in Boise, Idaho and we looked at Craigslist ads in Utah and Oregon. The farther you're willing to go to get a trailer, the more choices you'll have.
Finally, beware of folks who took out a big fat loan to buy their brand new trailer and are hoping to find a buyer who will pay enough to retire their loan for them. They owe the bank a lot more than the trailer is really worth. They'll insist that the trailer is worth their asking price. Don't be the guy that believes them.
Good luck!
