Where to buy a 2G Prius?

Hi! I've been searching for a 2G Prius up to $5500. So most likely a 2005 or maybe 2006. I've been holding out for one below 140k miles. However, so far I've been using KSL classifieds in my area to search for options but have come up with nothing for weeks now. Are there any reputable sites or something to check for a prius in that range? I have not found any on my own. I'd greatly appreciate any tips for finding a prius in that range and on how to check it and ensure it is in good condition (I have no experience with hybrids). Thank you for any help you may give!