We bought used for our first five trailers (tent, egg and three TT). When we decided to purchase a "keeper", we bought new. We looked at several used FW and they all smelled like a nursing home or perfume. We were told to just let it air out. Couldn't do it so we bought new. Our FW stays on our lot, will have a cover over it and is not towed from place to place. Should last a couple decades in that case.
In about 10 years when we are ready to start traveling around the country, we plan on buying a mid-sized TT. If we can't find what we want used, we will buy new again.