So far, all I've gotten was the option to use the 30-day demo since they never sent a serial number so it looks like I paid for the demo, which is usually free.
Except they haven't charged your card, so you haven't paid for anything yet.
Most honest retailers don't charge until they ship the product. I have had a charges come through a month or more later when a product backorder finally comes in for them to send to me.
These kind of websites pop up all the time. They are up for a couple of months and then disappear to reappear under another name. They usually hold and sell volume licenses, academic licenses, or a Microsoft subscription that gives them limited licenses at a low cost. What they are doing is a violation of the EULA on their part but the software will usually work just fine if they send you a key. They could also be selling stolen or cracked volume licenses. Microsoft and other vendors will turn off the keys they own and sell if they discover the fraud. That may or may not affect the license you bought when your program tries to update itself. It could turn off because of the pirated key or it might work forever.
Before you buy from any website, search for reviews. If you can't find any or they are only for the previous month or 2, don't buy from them unless you are willing to take your chances.