Walmart likes to rip you off for all computer add-on parts. It is like buying a cdrom at walmart for $29.00, when you can buy one on-line for $14.00 with $3.00 for shipping.
Word to the Wise is that Wal-Mart is not a good store for buying computer anything.
New Egg will beat Walmart on cost for computer items every day.
Before you buy anything for a computer, you should look on-line and see what it costs.
Many stores have On-Line stores as well.
Best Buy
Office Depot
Office Max
Staples
Sams
All of these stores sometimes have sales on items.