Hi guys 
Just got myself another project

So I have brought a gen 1, hayabusa 2000 model and I'm putting the engine into a yamaha raptor 700 frame , but I'm going to add a stage 2 turbo kit as well. So this is why I need the help. I visited a very well known local tuning shop to me, who explained what I needed and how much it was going to cost. 
His price was £1800. 00 for engine works, turbo pistons, HD studs, head work, timing chain, valves ect. 
The stage 2 kit all in fitted was £6500 so all in all about £8000.00.
The issue I'm having is with the stage 2 kit price, whilst I know I have to pay for the shops overheads, his experience, profit, just can't get my head around it, so hears what I'm thinking. 
If I buy my own stage 2 and fit it myself, (I'm good with a spanner) get him to do the engine work and to tune it. 
This is what I've priced up so for (all in pounds) 
Gt 28 turbo. £500
Plenum chamber £400
Turbo manifold £500
Air filter. £50
735cc injectors £200
Fuel pump £100
Tial bov

Tial bov. £200
Tial wastegate £100
Link pipes and bends £200

Rolling road tune £300
So this totals £2550.00
Some £3500 cheaper.. 

So my real question is, what else do I need and are my sums correct 

Sorry for the long post

Many thanks neil

Engine management?
Is that a used turbo you have priced?

Was going to get a pc 5 for the fuel management part
No that's a new price

Many thanks