I'm about to go hybrid myself and so I can give a pretty accurate brake down of the costs involved..
Now I think it's unfair to include cost that aren't specifically for the hybrid upgrade. Most people with a remapped 130 or 150 will (or should) have already sorted their brakes, panel filter and de-cat just to be able to get the best out of the standard turbo. Also as many people find out, the standard clutch doesn't last too long on a strong remap so you'd be changing it sooner or later anyway..
If your a 150 owner you don't need a new FMIC, but probably some upgraded pipework.
Mines a 130 so here's my breakdown...
Stage 2 Turbo Conversion at Turbo Dynamics £525
Forge FMIC (inc pipework) £440
Sachs Performance Clutch £660 (I don't think this is even a hybrid specific cost)
Remap £200-£350
Bits and pieces (replacement oil feed pipe, gaskets, oil change etc..) £100
Total Cost = £2320 inc Vat (If you own a 150 and have already done your clutch then it's as low as £1300!)
Results = 230-250bhp & 350-400+lbft

So for me coming from a 130bhp car, I'll have got a 92% increase in power
I'd say a bargin compared to what sort of gains you'd get from a lot of other cars for the same investment. Oh and I'll still be getting 50mpg when I want to...
