In general buy.com purchases can be a problem. They don't bother to keep realtime inventory so any popular/sale item may be sold out even though it clearly states "In stock" on the page. Personally, I consider it fraud, they have no justification to specifically put an "in stock" note up if they are not keeping the item IN STOCK when that note is appearing. That is, essentially, the whole core purpose of an "in stock" status.
Unfortunately, if you order something that isn't actually in stock, you may not (I usually didn't) get a notification of this either, you just wait, and wait, and wait, and check back on their 'site to see that it isn't shipping. Often the product page still says "in stock" too. How insulting. So eventually you cancel the order, wasting a lot of time.
On the other hand if they happen to actually HAVE what you order at a warehouse, the prodcess is smooth enough. In my mind that just isn't good enogh, if I order a part that says "in stock" or am not notified about the lack of stock the same or early next business day, they become an unreliable source. I suppose my main point is, if you are anxious to get it, buy elsewhere or check back frequently keeping in mind that you may need to cancel and reorder elsewhere- just be sure to cancel FIRST, and let some time go by to be sure they didn't then ship the order and fail to update the order status page. I've heard of that happening several times.