HELP! What is the value on these parts?

[GMC85HighSierra]

Hi all, I was wondering the value on these parts. The doors are complete but rusty; they came off of a 1990 Suburban. Looking to get the mirrors off of them mainly. Then he has a tilt steering column that has the GMC horn button I need, and I have a Chevy horn button. I just want to swap horn buttons, but he doesn't seem to want to. Also, the column appears to not have a key for it.

He wants $75 for the two doors, and $25 for the column ($100 for all). The steering column seems to be a fair price, since it's a tilt. I guess I just can't see paying $75 for the doors, since I don't "need" a whole lot off of them.

I would like to get the power mirrors for an 89 Chevy crew cab short box that I'm paying off. Want to make it look like a 1981 GMC single headlight with a stepside bed...? If I had the 1989-1991 Square Body Chevy front clip, I'd put the crew cab back to original. I have an 87 GMC, so I figured make this truck a GMC also. Looking to make it almost manual everything. Thought about power locks and windows, but then I think of it as another thing that can go wrong . Your inputs are appreciated. Thanks