quote for an upstairs loo

rammster

I have 1920s end of terrace 3BR ex local authority house in Dorchester , Dorset. I have a Family bathroom downstairs and want to construct a small toilet with a sink. There is no soil pipe and all drains from downstairs loo empty into gutter underground. Our plan is put loo on saniflow and then pass pipes on to the roof and then bring them down the loo downstairs (opposite corners <10m> ) and connect them to the soil pipe .
All inclusive of materials and labour (4-5 days) I have been quoted 2k. Says could even work out less than this. He has taken measurements and will issue me an official quote. The work involves moving a boiler and knocking a plasterboard wall down.
Do you think 2500 pounds all inclusive is a good deal. Would still have to pay the electrician for installing a light socket and an extractor fan. he will bring all the tiles and the pipes (4mm due to saniflo). Says could even go cheaper if I did the shopping he will tell me where to go as he is registered with a company.

Markinjapan

Can the one chap do the building, plumbing and tiling?
Also, does the quote include building/partitioning the room too (including putting in walls and door?)

We're thinking of something very similar, but downstairs.