The Retail Store Challenge (UPDATED)

Looks really pretty, dear @illusie ! :)
Small and budget is not the same, although small helps with the budget, of course. My advice is: use free and cheapest stuff (wall paint and floors as well) and try to be the most creative you can be with all these poor stuff! LOL To build with a small budget is most of times very frustrating but when you get it, and the result is even better that you ever imagined, you will feel like a champion!