Hi newcomer and welcome to the Tom's hardware forum.
Ok, 4 WD 500GB at 69.99 right?
4x$69.99=$279.96
Total: $ 279.96
For a similar price you can buy this:
1- One SSD 40GB like
this at $ 129.99, and add $30 more and buy 2x1TB of
this
Total: $ 309.97
2- Two SSD 40GB like
this at $ 129.99
Total: $259.98
3- Add $20 more and buy a SSD 80GB like
this
Total: $ 299.99
But is just IMO, is your money.