My proposal for you is a minimalist one, using light colors, except for the floor, which gives stability to the room. The white as predominant shade makes the room seem bigger, and also bring more light inside. The furniture is one with clear lines, light grey color. I was thinking to replace the door with a sliding door, so you will save a lot of space in the room.
Due to the fact the budget is pretty tight, I decided to keep the original location of the water pipes, sink, and drainage. The money will be use in a more clever way for realizing an elegant finish of the walls, using large tiles, for walls and floor, and also modern minimal furniture, and linear drainage system for the walk-in shower.
It was a bit hard to estimate the prices, but I wrote you the European ones.
If any other drawings would be needed, they can be provided.
Have a wonderful day, and let me know what do you think. :)