I haven't got a problem with it if they're not asking dealer prices either. If they only want as much as a private sale, there's no difference really is there. It's the scumbags who ARE dealers, sell cars at top price then wash their hands if somethings wrong that bother me. The higher price of the dealer should be to pay for their responsibilities under sale of goods etc.
Quite a lot really - a trade sale has lots more protection for the buyer / consumer laws / seller has many more responsibilities with regards to descriptions - fit for purpose - sale of goods etc etc than a private sale.
Sell it as private its basically buyer beware - if its a lemon tough luck.