Quick check on Bricklink for the one's I recall being expensive - the dark orange (30236) brick with handles are £5.80 new and about £2 used, 18 of those needed, the 2L white ribbed hose are running at about £1.50 new / £0.70+ used - 112 needed. And the various 78cxxx pipes, domes and harder to find slopes/wedges/tan elements are not cheap.
And as ever there is the LBG levers at their crazy prices.
Not available I think included the canopy, the large wheels in white, and some of the white technic parts are hard to get in sufficient quantities (I think one of the parts would need almost 24 orders for the 24 needed).
Throw in shipping costs as appropriate....
I agree with Soul, depending on what has been subbed, it could be decent price. I've got my excel inventory built but not yet started collecting/building prices.