Cost to install new tub in leaking shower sound right?

[Sam G.]

I have a shower that is leaking when used to the basement downstairs. This is an old leak that I thought was taken care of and apparently is not. So plumber advised that I redo the shower floor. I want to do the job once and its my biggest expense to date with my 1st house hack so I'm really hoping somebody can tell me if this quote sounds right please?

1. Remove shower walls to stud, put new greenboard, new tile.

2. Remove shower tiled floor, fix rotted wood subfloor, install new tub (with greenboard or whatever is used, not really familiar).

3. Replace rotted wood beam in basement under this shower 

4. Put jack in basement for extra support on that floor/beam

Basically its a small tub area that will be new.

Cost: $2000 with materials. 2 days work.