Selling A House And Buyer Wants To Change Price After Contract Is Signed.

Ok, so I'm selling a house left to me by a relative. It's being sold to two individuals who have an LLC they use for property management and real estate. They asked me to show them the house and I did so about three weeks ago. I showed them the house, didn't forbid them from looking at anything. We then negotiated as they are looking at this as an investment property not a primary dwelling for themselves and I was hoping to sell quickly. We agreed on a price, and I was presented with paperwork to go under contract. We filled out the paperwork and signed it with the agreed upon purchase price listed, and under the "Examination Period" section, they wrote in "As is - no due diligence", as both parties wanted to complete the sale quickly.

Now nearly three weeks later, and under 48 hours from our scheduled closing date and time, they have gone back out to the property (without telling me or asking for permission) and walked around the outside and took a bunch of pictures of issues and structural concerns, sent them to me and are now saying "it's going to cost too much to fix, we can't pay what we had talked about." And "when we left the house the day you showed it to us it was dark and we never walked around the outside completely" etc etc.

It was then suggested that we could delay the closing and go through the process of getting quotes for the work that needs to be done (they know I was hoping for a quick sale), or maybe we could just agree to a lower price, and then they suggested a price that cuts more than a third off the previously agreed upon price.

Maybe I'm crazy but are they not bound by the signed contract? I'm the noob in this situation having never sold property and I'm dealing with people who do this all the time and I kind of feel like they rushed in because we agreed to a certain price, and are now realizing shit there's more work to do here than we thought so our potential profit margin is slipping away, let's just see if we can get him to agree to a lower price.

Any insight would be helpful and I have a redacted copy of the contract if that would help clear things up.