In most fields, a seller's recommendations can be anywhere from ultra-conservative to ultra-liberal without it really being an issue of ethics. It would be nice, however, if the buyer would get a second and third opinion before pulling the trigger, or have access to a great forum like Pond Boss so they can see what another vendor might think. The only unethical practice I could imagine in this case would be if the seller implies that their's is the only reasonable course of action.
