The internet is a huge thing as you already know. Sometimes listings get scammed, incorrect entry, fingers hit wrong keys or some engine or geek has a fuzzy way of picking up. We as REALTORS get your question every day and (sorry it sounds so pat) having a REALTOR help you search alleviates this. You know if you tell us what you want, details, location you want and price you want, it is set up as an automated data base search and emailed to you daily. Yes you can find the perfect house, in the perfect location at a perfect price. It is amazing and fun too!
I don't know why there are variable prices listed, but it really doesn't matter. The list price is what someone hopes to get, the value is what something is worth, the offer price is what you determine you are willing to pay. These can be 3 different numbers, usually in declining order.
If you like the house arrange an agent to set up a time to see it, verify it's what you want. Ask your agent to run a CMA to determine the value and decide if you want to make an offer.