$64 is about how much it would cost for a 500GB plus an external enclosure, so it's not a ripoff by any means. Still, buying larger drives will give you more value though.
Not sure that's such a good deal. I get my 1T drives from Newegg. I've been getting this one: Western Digital Elements 1TB Desktop External Hard Drive WDBAAU0010HBK-NESN It goes for $69.99 and has free shipping.