What size of compost bin will I need

The local council subsidies compost bins - I can get a Komp 800 for £30, Komp 200 for £20 and a Con 220 for £8 - which size one would be best?

Assuming the numbers refer to the capacity the Con 220 has got to be the best value; if you have no bins at the moment then 2 or more is always a good idea (one "cooking", one maturing, one for storing finished compost - oh that's 3!!!!) 

I would always go for the biggest you can get and plenty of them, or make your own. It's surprising how much household and other waste you can compost once you get started. I've got two large plastic bins, a big open heap, two leaf-mould frames and half a dozen black bags of rotting material with the intention of being totally self-sufficient in compost next year. It's taken a couple of years to get organized but I'm spurred on by the thought of not having to part with my hard-earned cash for dodgy compost at been and queued.

I have found the black plastic bins the best for sweating down stuff and getting the process started. Once stuff has had a bit of time in the plastic bins and start to cool down then you can chuck it into a bigger pallet bin to finish the process. I found when I just used a couple of pallet bins I got stuff regrowing and it did not really get very hot. This year I have 3 plastic bins and once the first is full I lift the bin off the compost and chuck the whole lot into the second. Eventually this fills and repeat the process via the third into my pallet bin. You can never have too much compost! Like others have said I now offer to cut my neighbours grass and keep the cuttings while another bags his stuff up to avoid having to use the council green bin and just gives it to me. I repay him some onions at the end of the year.