I remember to have seen some offer about them but months ago.
If you have a smartphone you can download an app called katalozi, with all updated offers from chain stores..
In.alternative if you feel like adventurous there are big pvc pannels (30cm by 250 cm, I believe) with hideous prints sold between 9/18 leva. The are made to be easily connect. If you have a structure, or you can build one yourself you can try to make your own