How much for a refurbished shower en suite?

[Itgetsthehoseagain]

I've never, ever paid for home improvements, so I'm completely in the dark here.
We need our shower replacing (we want a walk-in one - less cleaning), a new toilet, sink, radiator, flooring - everything, basically.
How much money do we need to save?

We just did ours for about £4500 but I’d say that was the cheaper end of normal.