Under the multiple accounts policy (http://pages.ebay.com.au/help/policies/multiple-accounts.html) it says this:

Registering new accounts or using other existing accounts to avoid buying and selling restrictions or limits or other policy consequences.

A friend and I looked into this really closely when they started giving us 30 free listings on non-store accounts.  I'm pretty sure it said a bit more about using a new account to avoid having to pay listing fees but I have no way of knowing what it USED to say.  The first part of the policy talks about understanding that people would want to have different accounts to sell different products, so I thought it was fairly logical to assume the rest of it would be interpreted in that light, but I'll bow to superior non-ebay representatives' knowledge.