I would suggest you have answered your own questions really.
Champagne ideas, beer money.
Like it or not you are asking for a commercial system. That comes at a premium.
Although "warehouse" seems a little self aggrandising from your descriptions.
I'll direct your thread to one of the commercial guys in the CC and see what he says....
sorry, i may of called our storage area by the wrong name (warehouse)
its a tools and materials store area. its approx 9m x 9m with a 3m head height. so about the same size as two through rooms in a domestic property.
When i say racking, i mean the shelf things you purchase from B&Q.
Beer money or not, im trying to get other quotes. If the quotes are the same then that is what i pay. so far i have had 2 quotes with a 100k difference on a property that is around 2x the size of my house. i live in a above bigger than normal 3 bed semi. When i say bigger than normal then it could be about the same size as a average 4 bed house.
now correct me if im wrong but a CH system in a 4 bed house dont cost 10K ??? let alone no chopping out of walls or lifting floorboards etc. no harder than fitting 3 rads and a boiler all in the same room?