1978 chevy k29

i have a 1978 chevy k20 with the silverado package. it also has a 454 and the 400 transmission. is this a rare truck? could somebody please help. i know alot about trucks. i think this is a rare truck only paid 800 bucks for it and it is great running shape. i accidently hit the 9 it is a k20 not a k29 my fingers are a bit big and it is hard to operate a keyboard.  

some people consider them rare if they are in real good condition, as now it would considered a collectible, but it isnt extremely rare, if it was a k29 like you say it must be rare, i never heard of those, haha, but 800 bucks is a score if it runs great, hopefully the body is in good condition too, those are beautiful trucks