Hmm I don't see the house. I was only able to find 3 homes that sold for $240K in Lawrence ... where are you home shopping?
So, there is nothing stopping you from making an offer on a house regardless whether it is offered for sale or not. The only difference would be the reception on the offer and therefore your approach and presentation would need to be very different in that you may need to provide a motivation for the owner to sell.
If it's not listed for sale, you can certainly approach the seller...but I would still advise you to engage a realtor to help you evaluate the house, get all the required disclosures, determine a market price, and negotiate.