Firstly with these sort of machines as opposed to an appliance you cant really go wrong. If its under a year old, unless its been treated like crap it really wont cost very much even if it needs a major service to bring it back to brand new. Theyre very simple machines and not much expensive goes wrong with them. So AT WORST it will cost you about $250 to bring it back to life - assuming its been neglected.
If its under a year old and been looked after, and had a service in March 2012 it should be ok.
If you have access to it and can make a coffee and take out the mushroom etc then thats even better.
2/3 retail is reasonable should be somewhere between $1500-$1600.
To give you an example I own one which I am very fussy about. My friend also has one which is 16 months old and she NEGLECTS hers. Never done a chemical backflush etc. Whilst thats not ideal she just had a full service for $230 and now its like brand new! So they can take a lot of punishment and still be ok.
Not sure about warranty. Should be transferable I would think.