A really good condition ex250 '07- will be around $2k. Don’t even look at the '08+, cause those people buy that overpriced bike new and have no choice but to “try” to sell them used for a stupid price to make up for what they spend initially, after they discover that trying to look like you ride a 600 on a 250 will not fool anyone no matter how loud of an overpriced “exhaust” you have.
Actually if you just want a bike to commuter and not use it to impress chicks, you can buy crazy cheap ex500 race bikes that have title and convert them back to street use.