Mine are aftermarket chrome and you'd never know it. Chrome is chrome; there's only one way to do it regardless if they are commissioned by the factory or sent out and done after the fact. As long as they are stripped, prepped and done right by a good shop, there's no difference; sometimes aftermarket chrome will be even thicker. Unfortunately, there's no real way to tell if everything was "just right" when they were done, as you likely wouldn't run into any bubbling or peeling issues for a few years anyway. Some people look to see if the entire wheel is dipped or if only the face is dipped, but I don't really think it matters and isn't an indicator of quality for me.
I can say that that price is very good compared to the alternative, so I'd do it (in fact I did for about that price). Even if some sort of problem develops in a few years, it isn't a big deal to have them re-chromed.
As a side note, I had a set of very expensive (for their time) factory chromed MOMO Ferrari Engineering wheels on my Honda for eight years before I sold it and a couple of them started to bubble and peel a bit around the valve stems after five or six years. Still very minor and I never had them fixed b/c it just wasn't noticable unless you looked for it, but this is just to point out that there's no gaurantee that a factory chrome job is better than any other.