hello Fiona, when my friend went this summer (same tour as your parents) she bought a beautifull little bel from Plovdiv (totally handmade!)
So I guess its in the same material as your milk jug..
Those brown and blue home things (how do you call these in english??

) are def something to bring home..
Some little orthodox icons (handpainted) and the most important thing: rose-oil in mini-package
But what I really enjoyed this year is/was my buro-kalender that I bought in 2005 in Albena with painted piccies of towns and views! hehe
Somethimes its not the big stuff that does the trick