The RRP for the official HP TouchPad case is apparently somewhere around £40, though if you shop around, the typical prices range between £20 and £25, which I still think is quite expensive for a simple case. Yes, the case can act as a stand too, but I reckon that £10-£15 would be a more sensible price.
Thanks to HotUKDeals though, I just ordered the case from HP's Business Store for an amazing £3.96 (yes, free postage too). You have to use an e-discount code ("TPCASESAVE5") to knock £5.00 off the original price, so I suspect either the code will be discontinued soon or the stock will run out very quickly, so don't dawdle!
Yes, you can set a separate shipping address from your credit/debit card billing address, but be warned that they only have 2 short text fields for your entire address (minus postcode), which is quite stupid really. I'm getting my case delivered to work, but I had to shorten the company name to squeeze it all in!