OSB is cheap and performs well. Cover with 9mm plasterboard - also cheap. With the OSB underneath, there's no need to worry about using specialist plasterboard fixings.
Don't forget a vapour barrier on the warm side of the insulation between the studs. And remember not to puncture it when attaching things to the walls - so the thicker the OSB, the better
I wouldn't use Contiboard or chipboard in any form (apart from OSB) as it doesn't do well in the damp.
In my cellar, I've had good results with spruce ply - available for about £30 (4' by 8' sheet, 18mm thick) in B&Q, so presumably much cheaper anywhere else. It won't finish brilliantly, but is easy to cut and machine, and putting that under the plasterboard should work well structurally. I don't know if it would be any better than OSB though...