[nolemmings]

Barry, you're right--reneging is a bad thing. BTW, oral contracts are certainly enforceable, so long as they do not run afoul of the statute of frauds (concerning certain specific types of contracts). Jamie is similarly incorrect to assert that claims for breach of oral contract almost never prevail; in fact, they are often successful, you just need to prove your elements.

Here we not only have an enforceable contract, we have an admission of its breach. The material terms are also available to see in "writing"--emails in this case. As for damages, they could be measured in a few ways, oftentimes by the difference in what you had to pay to receive the cards elsewhere minus the contract price here. If scarce or unique enough, you could even get an order of specific performance--requiring seller to provide the cards he agreed to sell. In sum, there is an enforceable contract, and it was breached. The only issue of whether it is actionable is whether and what damages were sustained.