Not really shady. Dude wants 100 for the set and it's 30 to ship, mark the price down and shipping up. You pay the same, eBay takes less of his money. I think its a great idea.
I agree that nobody can tell by the equipment what is going to be louder but, there SHOULD be a very audible difference between a 140.1 and a 148.8. Besides, it sounds like the meter already answered your question.
Now that is a sexy motor structure!! How many projects are you working on right now? Don't you catch yourself flipping numbers around on accident? Lol!