Matchbox Revell Ford Escort XR3

Is this model rare? I got my hands on one for like $40, the seller said it was pretty rare.

EDIT: While looking at the chassis I found some text. Appearantly, this kit was made in 1981. The text said "Copyright 1981 Revell INC".

They are not kits that you can buy off the shelf, but they do crop up on ebay now and then. Fairly rare, I suppose. I have not seen many that go for big money.