Cost/Price is really going to depend on how much of a rush you are in to purchase.
When I first started looking I could find 22.5 OTS's all around me all for below $40. When I was finally ready to pull the trigger I couldn't find one near by. After about 3 months of searching CL everyday I finally broke down and bought one at Fred M's during their fall closeout for $60. I still feel like I paid too much.
Less than 2 weeks later a 22.5 OTS popped up on CL about a block from where I live for $30 and it included 2-20# bags of Kingsford Comp. I jumped on that right away. Shortly there after I have seen them within a reasonable distance for $40 or less.
If you are not in any rush just keep looking and one will pop up for ya. Right now I am looking for a 26, but have only seen one listed and it is too far to get, and the guy basically want the same price I could buy one at Home D. for. I'm trying to be patient though...we'll see how long I last.
Good luck with your search