visit thrift shops,always,,before opening your wallet to buy one elsewhere in retail world
upscale audio viz,visit them,listen look flick the flicker click on music concerts,note pic quality,stability,,,
problems abound in getting one unseen,over the internet shopping sites
take notepad with in your shopping tours,get model numbers of those you like,and write down in thick red pencil those that you dislike.
like buying a used or new car,take your time
try one out,kick the tires,take notes make up your mind.