On a budget, the Zoom R16 is probably the cheapest way to go but you only get 8 inputs.
This isn't necessarily as limiting as it may sound since you can achieve a decent live
recording with just 4 inputs. Two inputs for the stereo output of the FOH mixing desk and
two inputs for ambient mics to pick up the crowd, room and anything that is so loud on
stage that it isn't going through the FOH mixer. If you want to use more inputs you could
see if the FOH engineer is using subgroups and take the outputs of the groups to the spare
Beyond this, I'd invest in some preamps with ADAT outputs and hook
them up to a standalone hard disk recorder. You may also need some splitters - I made my
own passive splitter multicore but I've found that venues with separate monitor desks
sometimes have spare ways on their splitters that you can use.
JRP Music - Audio Mastering and Restoration.