Arabian Nights actually has many cards reprinted in later sets. Many cards from Arabian Nights were reprinted in Chronicles, the later compilation set. Some other notable cards were reprinted in later Core Sets and expansions. For example, Desert was reprinted in Time Spiral).
Only 28 cards from this set have never been reprinted, and 22 are on Wizards of the Coast's reserve list. Being on the Reserved List means that they will never be reprinted, mainly because of their power level and also to protect their collectors value. These 22 cards remain some of the rarest cards in all of Magic.
However, in the first print run of the set, Mountain was accidentally left in. This makes the Arabian Nights Mountains highly sought after by players & collectors alike. A single copy of this particular printing of Mountain is worth about $50-60 USD. Even in less than perfect condition, they're worth holding onto, even if only for trade stock for Red Deck Wins lovers.
Stick around for more Retro Magic, where we look at some of the oldest and rarest cards in Magic: the Gathering!