It's a question of stock and manufacturer limits. For example, if Crucial says you can sell X units at this sale price (of which Crucial will take X amount lower than it normally takes for each unit), and forums like this one send a rush of people to buy that stock, the deal might be over before the 48 hours ends. It's in the fine print on every Newegg deal. It's frustrating sometimes, but it's rarely Newegg's fault directly.
This was a great deal, but they've been coming up lately...keep on it and you'll get on one soon enough. Also, you can sign in to Newegg to get price alerts on certain things, and then you'll never miss a deal. I've done that before with SSDs and RAM, and it works very well.
EDIT: Also, if you're still interested,
Amazon has it for $230 shipped.