http://www.ebay.co.uk/itm/Bachmann-31-514-Class-159-3-car-DMU-South-West-Trains-livery-SWT-158-170-/220996348599?pt=UK_Trains_Railway_Models&hash=item337468aab7#ht_500wt_1287
How much? I'm sorry but for what is, essentially, a repaint of a 158, it's a bit steep, particularly when you could pick up a 3 car transpennine for roughly 50 and have it professionally modded for significantly less than that.