To answer my own query on the returns issue:

> Restocking Fees: Unless the product is defective or the return is a direct result of a Dell error, Dell may charge a restocking fee of up to 15% of the purchase price paid, plus any applicable sales tax.

http://www.dell.com/learn/au/en/aucorp1/policies-returns (Aus version as this is where I am).

That's a real problem for online purchases in my view.