Apple Store's 2.5 hours away, and I just dropped $170 on this one. I guess if it doesn't work, I can always sell it. The extra $170 would be nice.
Ah, the joys of e-bay.
Sometimes something is too good to be true.
I do hope this works out for you. But, it may not.
The problem, is that many people (myself included), would not purchase just a code without some form of guarantee.
One option would have been to pay with PayPal and choose the option to buy the satisfaction guarantee that provides a refund. But, I believe even that only applies to physical merchandise.
But, with PayPal, you can still get a refund for shipments that never arrive. But, even that may still require it to be a physical product.
Purchasing keycodes is such a gamble. Without a package to back it up, I would question how they came to posses the keycode and if it were legitimate.
As for time constraints. You are required to register the keycode before the last day of your warranty.
But, I have been in a similar situation with my wife's iBook G4.
I waited until about 10 days before the warranty expired to order AppleCare for it (we kept putting off the expense). But, I ordered directly from Apple. I explained the nearing deadline to the salesperson at Apple, and he assured me that he'd place a note in our file to assure that we could register it if the shipment arrived a day late (it was scheduled to arrive very, very close to the deadline).
The package arrived the day before the warranty expired, and I registered it right away. All went well.
The thing is, in your situation, you'll be relying on Apple's graciousness to activate Applecare beyond your standard warranty period.
There have been cases of people getting Applecare activated one or two days after the warranty expired. But, it is something that is handled on a case by case basis.
If you want assurance that it will work, then you need to do it before the first year is up.
In your case, I would go ahead and try to register it immediately after you get the code (hopefully a legitimate code). And, if it doesn't work, then you'll have to call Apple.
It's a bit of a concerning situation you're in now. You've got money invested in something without a physical presence.
If you had ordered a retail boxed version, then you would have had good odds on getting your money out of it. In that case, I'd have done the following:
Once the retail AppleCare arrived in it's SEALED box, I would call Apple. I would explain the situation, and my concern of the deadline being passed. Then, I would tell them that the box is still sealed. And, that only if they assure you that you can still register it, that you would open it and register it on the telephone with them.
If they agree, then open the box and register. If they disagree, then sell the package to someone else.
But, in your case, all you've got is a keycode, and the hopes that you'll receive it.
It's an unfortunate spot.
In your same situation, I probably would have purchased directly from Apple with their assurance that they would let you register it if the package arrived after your deadline. Or, I'd have driven to the nearest store and purchased in person to avoid the questionable delay that adds uncertainty.
In your situation, a 2.5 hour drive would have been a worthy investment. Where I am, that's just a trip to a well stocked store with good prices (or commuting to work to get more than minimum wage). And, our people do it on snow and glazed ice for 9 months of the year.
I'd have invested the travel time to remove the uncertainty and risk. But, if not up to the drive, I would have just called Apple and worked-out a deal with them to purchase it with assurances (like I did for my wife's system).
I do hope that you receive your keycode quickly and that it does work for you. Best wishes there.