Shipping might hurt a little. Although, if you have a couple of people to go in on some kegs, buy 16 of these "B Grade" kegs from kegconnection.com and get free shipping. Equals out to be $19.99 / keg.
I saw some pin locks on cornykeg.com for 16 a keg if I didn't already have ball locks I would be making the switch. I know parts cheaper on the ball locks too. But for 16 thats a head scratcher.