That might've been us!
Local markets are great for fresh fruit and veggies, bakeries for fresh bread, but for everything else we found Lidl to be by far the best price/quality balance for everything else. Milk, beer, wine, meat, grains, canned foods, and even the odd boat part. Once you get to touristier parts (e.g. the Algarve, and most of the western Med), there will always be a notorious tourist trap shop (often a "Spar") near the hotels that sells basic food stuff for outrageous prices (e.g. a 1L carton of milk for 2 EUR when it costs 0.59 EUR at Lidl). Discounters are often a taxi ride away, but usually worth it if you stock up in bulk every few weeks (Bavaria's dry bilge sections are great for this - we have one full of milk, one full of cans, one with beer, etc. - keeping these heavy items as low as possible).
Restaurants are not for everyone. We rarely visit them, less than once per month usually (depends on where we are). When we do, we try to find the ones the local folk go to, not the ones aimed at package holiday tourism.
Most of the time we cook on the boat. We both enjoy cooking and over the years got pretty good at it. The first mate likes to look up local recipes on YouTube, buy the ingredients and then cook them herself. This usually works out very well, and most of the time we eat better on board than you can in many restaurants, and for a fraction of the price. This matters to us, as we're budget cruisers!
