Making a full price offer on real estate--even an over-asking-price offer, for that matter--does not require the seller to sell it to you; unlike many other contexts, in real estate, the seller has enormous discretion to decide what offers to take, who to sell to, etc., and can refuse an offer (while still listing the house) for any reason, including simply not liking the potential buyer (or thinking that if someone offered full price, if they hold out, maybe someone else will offer more than asking). The one exception is, they cannot refuse to sell due to race, color, religion, national origin, sex, disability, or family status. If you feel one of those reasons is behind their refusal, you may wish to contact HUD to file a complaint.