Please don't take this as me being a jerk, but it amazes me how naive people are. There is a reason people always say, " Never, EVER EVER EVER mix money with friendship". Its something that I've always tried to follow in my personal life. You honestly think I'll take some random dude's wprd on the internet?
I think you should have honestly been a bit smarter than that. I'd personally ask for half upfront or worked out a deal where you were not getting screwed over. I mean this isn't something new. Especially WoW which has attracted a lot of different players from different genres, its never been any truer. You don't have your typical "MMO" fan(boy) that follows a set of unwritten rules and code. I've had numerous douches pull such moves in raid runs, etc.
The sad thing is I'll often get people that actually think everyone behind a female dwarf/draenei avatar is a female. They literally throw gold at you. I've played the AH as a female draenei and on a male character. OMG you would never believe the deals I've managed to pull of on my female draenei. I've got massive discounts from sellers, sometimes even free stuff.