This is why most people shop on eBay - to get some of those dirt cheap internet sales all the kids are talking about. At any given point there are literally thousands of auctions, providing plenty of choice. The good news is that there are some great deals to be had. The bad news is that none of those deals involve new-in-box (NiB) product.
eBay has an undeserved rep for hosting tons of dirt cheap auctions on brand new merchandise. Five years ago, this was more true, but with the elimination of Outrider discounts, the cracking down on discounting by US stores and webstores, and GW making it tougher to open a retail account, new product tends to hover between 15-25% off of retail, once shipping is factored in!. "I can order anything off of TheWarStore for 20% and free shipping!" I hear you say. My response is to simply shrug my shoulders. I did a half hearted search on eBay for complete auctions for Tactical squads, and the NiB squads sold for between US$29-$34, after shipping.
The point is that eBay is not a really good place to grab NiB stuff. Bigger auctions, with multiple boxes and/or army deals, can be better deals, but in general the new stuff is simply too expensive. There are some great deals to be had on eBay, but they involve large lots of used minis. With paint stripping and some patience, all metal models and many plastic models can live again, despite the hideous paint job of the previous owner. I've had Falcons with literally three layers of paint clean up nice and neat. Keep in mind that many plastic multi part models can be poorly assembled, which is far more difficult to fix then a bad paint job.
Make sure you pay careful attention to the shipping prices. A large number of sellers will have high shipping prices in an attempt to recoup their costs from eBay, and you must take this extra cost into account when planning your bids.