Buyers potentially backing out

Location: Texas
Background/context:
We’ve had a contract on our home since the beginning of May, closing date of 6/18. Option period ended 5/17. The original inspection had a potential sewer line issue, offered the buyers 4K of the 6k bid to replace sewer line on 5/15, they said no-wanted the line scoped. That plumber said it was in good shape and to jet the line. Agreed to jet it in addition to fixing a couple other issues. Jet the line for $400. Buyers want the line scoped again (which we oblige to do at their cost), then they come back and say they now want the line replaced, the bellies were bigger than originally thought. I should note the same plumber noted that the jetting worked, the line is in good condition, and it drains properly. Offered up a workable solution to get the line covered as we were about 2400k apart (we would split the cost between us, their agent and our agent just to get this deal across the finish line). They are now saying their agent shouldn’t have to pay anything (it’s only $800?). We’ve now wasted a month+ on these buyers and I genuinely don’t think they’ll show up to closing next week even if we all agree on a fix.

We know they are first time home buyers, and a relocation. I truly don’t think one member of the couple wants to move and it’s actively sabotaging the deal at every point.

We’ve been told legally we are in the clear and have upheld our end of the agreement, but (1) I just needed to vent and (2) legally what all can I go after them for?? I know we can get their earnest money, but I want to go after them for everything I possibly can. I am over these people. I believe if we end up selling for less we can go after them for the price difference as well as other costs incurred. Anyone else experienced this? Thoughts? Suggestions? TIA