depending on how lucky you are and how willing you are to work it...
i have a 120 gig WD and an adaptec combo enclosure for 19.99 after rebate.
details on original deal
what i did to get it to 19.99 + tax:
went back to PM to Staples but i told the CSR i would really rather get the drive that was onsale this week. she said fine! i went and got the WD 120 gig with $60 in rebates, used the coupon so it was 79.99 even with the maxtor but $60 in rebates... so
drive + enclosure $79
return and repurchase the wd with -60 in rebates and -20 in coupon
79-60 = 19 for this deal
i even showed the girl what i did since she said she was going to buy an external... it was priceless watching her grasp what i did