There are several reputable outfits that remanufacture turbos, probably would supply one for less than half that price - if that £1500 included fitting it still sounds a bit steep, I suppose lots of dismantling to get at it at dealer's labour rates would account for a tidy sum.

Funnily enough my turbo went pop on my 90000 mile 2002 320d a few weeks ago. My excellent BMW specialist in Yeovil gave me the parts choice of a recon and guaranteed turbo from a company near Fordingbridge, Hampshire for £450 + VAT, a Garrett new one for about £800 + VAT or a BMW one for £1100 + VAT.

I went for option one and the overall bill including an oil and filter change and manifold removal/refit for cleaning with total labour (£150 + VAT) was a very reasonable £763 all in.

So if you have a good BMW specialist near you it can be a lot cheaper. Be careful the delaer does not try and insist the cat needs replacing when often they just need a run to clear out ant residual oil (depends on how much oil went into the exhaust (if any) when the turbo went if it went in a dramatic way like mine).

Good luck!