I always buy wholemeal ones from the supermarket (about 12p each) and we have a great little grilling machine, which has certainly got its £15 worth of use over 4 years.
This isn't really a recipe, just to say wraps are a great idea that tick off my 3 factors for student eating: cheap, healthy and delicious.
In this one I added pepper, cooked roast chicken thighs (much better value than breast in the cooked meat section of the supermarket), some light mayo mixed with some chipotle paste, some coriander, chopped chilli and some slithers of cheddar. Put in the lean mean griddle machine for 5/10 minutes.
This was lovely with some radishes and sugar snap peas.
Wrapping is like rapping, you can make it up as you go along and you just get better and better at it!