if there is one game that every single gamer should own (or at the very least play) this is it.
gameplay-younger players only familiar with newer entries in the series might miss some of the moves and items added in the sequels, but on its own merits the gameplay is flawless. not to mention groundbreaking and highly influential.
graphics- when comparing it to nes titles as a whole, this is the one area where zelda doesn't shine above all other games. however it was possibly the best looking game of the early era. just be warned that there is a little lagging when too many enemies are on screen at once, which is not uncommon.
sound-this is usually what brings down a lot nes games. those old, limited game scores can get on anyone's nerves when they play over and over. but zelda's themes have yet to get old even 20 years later. also, the sound effects may be primitive but they're iconic.
value-it's hard to say since its long, long out of print, but you can get it on ebay cheap enough. plus its been ported to the gba, gc and the wii's vc, the last of which is only $5. you should have no problem finding this game at a reasonable price.
tilt-its the best game released on the nes; it led to the best video game franchise on any system; and it has left a greater impact on gaming than any title save perhaps mario. a masterpiece.