Besides the series 3, a couple of the gitd and the pine great beast, they've all come from bundles that have cost around 50p a figure. I started collecting with the intention of just buying bundles to keep the cost down but I caved in a few times and bought single figures. The series 3 cost just under £35, which is still pretty good I think.
Ive got a load of regional too colours from the same bundles and something like 800 common figures which I need to sort through lol.
I'll probably keep collecting the same way-going for bundles with premiums in, the common colours will look after themselves.