The best deal on drives is definitely through Staples with an Amazon price match and a $30 off $150 online coupon. It's very easy to do.
First, purchase your $30 off $150 Staples coupon from ejunkie or eBay. Usually costs around $2
Next, go to staples website and order your drive using the coupon. The Seagate Go Flex is $179.99 so your total after coupon should be $149.99. Keep your order # handy.
Finally, open a customer service chat window or call the Staples customer service line. Tell the rep that you want to do a price match from Amazon on an item you just purchased. Give your order number and the rep will find the item on Amazon. They will then refund you the difference from the ORIGINAL Staples price. So if you purchased the item for $179.99 and Amazon has it for $139.99, the rep will refund $40 to your credit card. Final price after coupon = $109 + tax
PS: I was able to do this with several times and got great deals. I purchased a 128GB Crucial M4 for $110, and an Antec Three Hundred case of $25.