I'm possibly about to change jobs and am trying desperately to figure out how much it's going to cost me to get to work if it comes off.

I currently split my week pretty much 50/50 between Kent & Hounslow (where he-who-thinks-he-knows-best lives) and I've got prices for trains from both locations to Waterloo but what I really need to know is how much it would cost for monthly travelcards on an Oyster for zones 1&2 and zones 1-4 so that I can build up a clear picture in my mind of whether I'll be able to afford to say yes if they offer me the job!

Also, can two people share one Oyster travelcard so that if I had a zones 1-4, himself could use it on the days I'm not going to work from his place if he didn't fancy cycling to work (which is what he usually does)

If the above is allowed does anyone think that it would be best if he got a 1-4 and I got a 1&2 so that all my/our options would be covered.

Blimey, this new job lark is trickier than it seems!