where are you checking the temperature for? Sunny Beach in Bulgaria is really warm in my experience.
Bulgaria is cheap - we paid �210 for bed and breakfast in a four star hotel. I'd really recommend a holiday there, especially before Bulgaria joins the EU.
The food isn't excellent, but it's certainly edible. There are some very reasonably priced restaurants that serve delicious food, but there's also rubbish ones, pretty much like everywhere. If you stick to the usual holiday guidlines like not eating food that's been sitting out and could've been reheated etc then you'll be alright. (and there's always mcdonalds...)