I live in former family home and I remember my bathroom looking like that at one stage - scary.
My bathroom layout is walk in door to see toilet directly in front of me. Small window to the left of that and sink on the left hand wall (not cornered or centred but closer to the window end than the door). The shower in then behind the door in the left hand front corner.
Recently got bathroom revamped (from same layout) at cost of c€4K if I remember correctly although it may have been a little less. Price included all materials and suite etc.
The guy that did it was excellent and if you're in Dublin I can pass you on his number. He did all the work incl electrics, tiling and plumbing etc.