Hi again
overall, supermarket prices are comparable to the UK, some more expensive, some less - I live in Gozo, so ask for any specific items, but in terms of bringing things from the UK, there is nothing I'd bother to bring from the UK (unless its some English bottled beer for me !)
more expensive
anything light and low value but bulky, so high shipping costs eg breakfast cereals
less expensive
alcohol except spirits, cigarattes, vegs, meat, bread
where is the villa, and will you have a car ? Does the villa have a pool and air conditioning ?August will be either hot or very hot.
In terms of other things, you've already made the most important decision and chosen Gozo