Tin Man, what you said has been done before by many. Nothing new. And it can backfire if your goods doesn't sell because too many people are reselling/undercutting.

And keep in mind your PM still decays 1.5% per turn during the market sale 4-5 hour trip (lets say this is 13 turns, almost 20% of your PM would have decayed away). It's a lot of decay on a huge PM.