Just because you have a cause of action for breach of contract (the law recognizes the other guy should've kept his promise) does not mean you can get the remedy of specific performance (where the other guy is actually ordered to make good after all). The standard common law remedy is _in specie_ damages (the other guy has to pay up). The exact rules about when the court can compel specific performance are messy (written by lawyers), but it seems to me that basically what they all come down to is that no judge is going to say "I compel performance" if there's no feasible, relatively hassle-free way to actually, physically, compel performance. And that, in practice, tends to mean cases where the promise was title (legal ownership) to property: the judge can make the promise be kept by simply awarding the title to you. Actually getting the other guy to give you the cow or get off the land that's newly yours is a matter of property law, which has procedures such as replevy (where the Sheriff waves a gun around while you take the cow) and ejection (where the Sheriff waves a gun around telling them to get off your land.) These things can get messy enough as it is, and no judge wants to be responsible for having a sheriff waving a gun around to, say, compel somebody to give you a haircut. (And a GOOD haircut too, or else I'll shoot!) In such cases, the tricky specific performance business is transformed by the law into a straightforward money debt of the sort that can be enforced using, you guessed it, Sheriffs with guns, as well as garnishment of wages and the like. (I'm pretty sure that in the US, though, debts arising from judgments in breach of contracts cases are dischargeable in bankruptcy. Don't trust me on this, but I think it's pretty much only tax debts, student loans, and judgments for "intentional" torts that aren't dischargeable.)
All right, so after that long paragraph full of chattels and replevies and Sheriffs, if you are still reading, let's just assume that what could be had in court was monetary damages.
How much?
Oh, I would say about $500. Maybe a small multiple of that, but how are you going to convince a judge that you paid $500 for something that is worth much more than a small multiple of $500 to you?