Depends where you eat & drink.

Djanny's and the Condor (both near the outdoor market/main road to Bourgas) are among the cheapest and most 'Bulgarian' places - very good food and prices - two of us lunched with plenty of drinks for 10/15 Leva last year.

Prices increase in the main resort area and hotels.

I totally agree with Djannys & Condor, but there are a couple of places further back from the market that are really cheap. Can't remember what they were called though.

Even so, it is still cheap enough where ever you go....

we stayed half board

but did eat out quite regular 2 adults and a 13year old

a steak meal for 3 a couple pints each for the adults and a couple of pops for the young one

under £20,

for lunch you can get a baked potato with as many fillings as you like for 4 leva about £1.50 or a chicken kebab for the same price with what ever fillings

pizzas are pretty cheap and a good size between 6 and 10 leva under £4

drinks vary in price depending on what you drink a bottle of becks 4 lev about £1.50
local beer 2 leva per pint about 70p, pop is about the same price

Mcdonalds is a few pence dearer than at home

Yes I noticed McDonalds was more expensive than home. I also recommend Djannys. Barbecue Credo on the front is also very good. The Happy Duck isnt too bad. Had a mixed grill from there, steak was burnt to a sinder, other than that it was ok. Around 4-5 pound for a meal for 2 there. Beer is very cheap, try the Karmenitza, there own brand of beer. Very very nice, thats all I drank over there apart from the cocktails which are buy one get one free. Beer is around 1 lev and the cocktails between 4 - 9 lev, but are BOGOF.

Accomodation, the Globus looks fine for kids. I stopped at Hotel Zora, which I recommend. But its a smaller and quieter hotel than the big places but the accomodation is very very good.