Di you dont guess ANYTHING, just select CALCULATED postage, and put in the exact measurement of the parcel and the exact weight.. it is all done automatically then, calculated by the computer when an eBay buyer looks.... you do NOTHING but the weights

yes you should choose Registered Parcel Post as the option, to cover yourself in case of a paypal dispute.

once he gets the hang of selling, get hubby to check out CLICK AND SEND, it's an aust post delivery choice that is cheaper than registered, and provides paypal protection too.