I have a 5 year old Toshiba, I think TW65HX81 and it still serves me well. We had a TP50H60 which we gave to a good friend and I believe that one still functions well. For these "old" sets, first thing to look for is burn in. Check the whole picture out, see if there r "imbedded logos" on the screen which do not go away. If this is present, walk away. Look for color inconsistencies..like too much blue or red or green. These in my opinion can still be adjusted thru the menu. I once adjusted the colors on an old Mitsubishi set that was all around blue. Took me about 30 minutes after which the owner said its as if he has a new set due to its more vibrant and lifelike picture. If ur cousin does not do the usual "maintenance" on RPTVs, then the convergence must be out of whack, i.e., green outlines on the left and red outlines on the right of objects on the screen. This again can be remedied via the menu on convergence but more comprehensively by the service menu.
As for price, u should not pay more than $300...dapat nga eh..pamana na lang sa 'yo yun. Understand that it can output progressive scan but its not widescreen and not HD ready. But mind u, upgrading to a 55" from a 29" is monstrous! That's almost twice the real estate!
For maintenance, u should tweak the contrast and brightness down and adjust or calibrate the colors via Avia or whatnot. More importantly, the convergence should be check every so often as this thing will "drift" off giving u a nasty picture. With regards to lamplife, don't know about Pinasside but here, the guns, (not lamp) will last a decade or so with only a part giving out every 5 years or so. My TW65HX81 just had the whole set of flybacks or something which attaches to the guns replaced for just $150 and the tech said that would last me another 5 years.
But all things considered, the set is old and obsolete. If ur budget aloows, liek Turismo says, look to something better, LCDs or DLPs. If however, mura ang bigay sa 'yo....presyong kamag-anak ika nga, sige tira pare ko!
