I definitely see what you’re saying about the seller backing out being a violation of your good faith agreement, and what is the point of a contract if the seller can just change their mind… However in my experience most people do end up settling for monetary damages incurred rather than trying to force the sale.
I have seen two cases where it went the distance and the buyers successfully sued for specific performance. The first was a $10M historic property in Downtown Denver that was truly unique due to its location and age. There are no other properties like it. The buyer had performed at closing, delivered funds to the title company, signed closing docs and everything. Seller decided to back out at the last moment for some arbitrary reason and just didn’t show up to closing to sign the docs. Closing funds were held in escrow, buyer decided to sue for SP. Eventually after about 3.5 years the buyer did prevail. I’m not sure who paid legal fees but they must have been significant.
The second case was a commercial property (an 8 unit multifamily in a complex of 6 individual 8 unit buildings), owned by a group of investors. A developer had already worked out deals with the owners of the other 5 buildings and finally got the 6th and final building under contract. Some of the owners had wanted to sell and others didn’t. I believe the owners with the majority ownership share forced the others to sell, but they weren’t cooperating. They all had their own lawyers of course and it was a mess that took 3 years but eventually the buyer (the developer) did prevail. I think the key in that case was that the property was the last one needed in a large development of a group of blighted small MF buildings that were to be torn down and redeveloped. The building was vacant and completely rundown with the windows all smashed out by the end of the lawsuit. The owners were essentially slumlords. The buyers had invested a lot into the deal (~$100M) and purchasing the property was critical to complete their development.
In almost every case involving vanilla SFH's that I've been privy to, buyer and seller have settled during mediation for monetary damages. In a few cases the buyer has moved forward trying to sue for specific performance but eventually gave up after about a year and around $30k spent on legal fees.
The gamble is that the outcome hinges upon the courts discretion and it's rare to see specific performance unless buyer can demonstrate that monetary damages aren't enough to make them whole. As an investor looking to purchase an STR in a ski town, I'm not sure I'd feel that confident in a court deciding in my favor, personally. Seller might claim that the contract wasn't fair and equitable to begin with, or use stalling tactics, or they might say they need to move into the property because they are getting divorced/ lost their job/ need to move their ailing mother into the property, etc. and anything along those lines might make a judge more sympathetic to them than an investor buyer looking to turn the property into an STR.
I’m also not quite convinced that the property is unique enough to justify specific performance because it is typically only enforced when there is a lack of other remedies such as monetary damages. For example the property being historical or a critical part of a large development plan. You could probably just go buy a different investment property and achieve the same returns. So that will be a tricky element to this IMO.
But I get where you’re coming from, it’s super lame when a seller backs out. Keep us posted on what your lawyer says if you can, let us know how it goes, and good luck.