I’m thinking of getting a life‐size model of a limited express train with sleepers but they’re limited edition and only three will be sold in Japan.
The selling (販売) of something has a limit (限定). This kind of item is one of limited edition.
This is a jukugo word, which usually means on'yomi readings from the kanji. If you know the readings of your kanji you'll know how to read this as well.