Hi and welcome to TTC!
I am using a CBFM, which I got on ebay (still sealed) for ??55 including a box of 20 sticks! The lady who was selling it got her BFP before she needed to use it.
Have a look on there for a bargain, even a second hand one would be fine, as all you do is put your stick in the monitor, so not like sharing anything horrible!
Easy to use too
Good luck! xx
TTC since September 2010
Chemical pregnancy in November 2010 - obviously wasn't meant to be
Keeping my fingers crossed ever since!