Be sure to check out this place, Cafe Louvre in Prague. Got some excellent grub at decent prices. They also have hot dog stands all over the place that serve those proper german bratwurst sausages. Load im up with onions and some mustard and you're set. In Budapest, there's this huge food market that has some hearty and cheap local food upstairs. The name escapes me at the moment but it's across the bridge that's opposite to Gellert Spa. Hope that helps. Enjoy!