We picked up the insulation on sale, it was about £10 per m^2 + £30 local delivery. Given width between joists and such it was slightly more efficient for us to buy slabs rather than rolls. Ended up with very little in the way of wastage, maybe half a bucket worth or so.
The netting was about £30 for a 1mx100m roll. Not sure what we'll do with the rest of that. Hopefully find someone who can use it in their garden/allotment.
Probably spent another £15-20 on staples too.