This. If the item I'm selling is meant for level 45-60 players, I'll barely undercut the lowest bidder, assuming I undercut them at all. But if it's for someone below that, I just sell it at whatever price is reasonable.
I started with a new character recently and found that I couldn't afford any more than one marketboard item even after saving up all my Gil so far, and selling all monster drops and Allagan pieces.