Newegg.com has the Antec Neo Eco 620C 620W Power Supply (ATX12V) for a good price.

Google Products Price : $72.98 ~ $99.99 Shipped

1. Newegg Price : $69.99 Shipped
2. Use coupon code EMCYTZT1291 to get $15 off
3. Rebate Price : -$20.00 ( Exp : 3/11/12 )
Final Price : $34.99 Shipped After Rebate