Dry ice usually gets sold in 10+ pound amounts at about $1 a pound, cheaper in mass of course, kind of similiar price range to bags of ice at the convenient store, it gets pricey only because you also have to pay freight on the ice and the stuff its keeping cool. I do happen to know - for some rather bizarre reasons - that FedEx actually does do dry ice shipments to Europe with a max package weight of 150 pounds and that you're typically paying about $8 a pound to ship to Europe on 2 day schedule, if you figure you're doing roughly equal quantities of burrito to dry ice you are looking at around $16-20 a pound for your burrito cost, or about $4-5 a burrito... ironically what you're are apparently paying. I believe there are actually some online companies that specialize in shipping items this way to travelers suffering grocery nostalgia in foreign lands, they might be cheaper. Alternatively tortillas are pretty durable and I'm sure the other ingredients are all around, Europe's not that backward about grocery options, at least Germany wasn't but that may not be a fair comparison, so ultimately you are probably better off just making your own and freezing them.