I have a panasonic 42pz70b plasma and want to upgrade to a 50inch plasma (prob lgpk350) . just wondered what my old one is worth ? its mint and been on wall since day one , 3 and half yrs old and came with 5yr pana warranty , original unused stand , remote , instructions , original purchase reciept 1200pound ! and pana warranty card and letter , no marks , no scratches , no dead pixels etc etc . just wondered what its worth ?