Picky,
I bought a share in a Barton based aircraft earlier in the year, I now try and fly once a week where before I was similiar to you doing an hour or so every month.
Buying a share took a long time for me to decide , but has definately been worth it .
My flying costs have dramatically decreased! I know you will have an initial outlay , but you are never really going to lose on the initial capital outlay.
Last night I flew for an hour and 40 minutes in an Archer II - 181 my costs for that were £63 including a quart of oil + £15 for the hour.
Now if you were doing that in a C152 or a Robin (2 seat ) your costs im sure would be less than that.
It has improved my flying with the increased continuity & I have my keys-book out-& go !!!
EL