I am not sure I would characterize offering an unlock code for a fee as despicable. He's not forcing you to use his service, just offering it. I chose to call T-Mobile and request it for free, but that being said, I have certainly paid for unlocking in the past.
My (unrequested two cents), call TMO and get the code emailed to you. If you are not eligible, playing someone to do it is also an option. There have been reports of the phone not connecting to any networks after unlocking. If you get the code from TMO, at least, you might have some recourse if you have to return the phone.