Rust how much is too much?

[Seabee6768]

Looking to buy a 1972 GMC stepside short bed, that has small bubbles surfacing through the paint. It's located on the bottom of door and rear quarter panel.
Small amount of what appears surface rust where the carpet ends by the rocker panel where the chrome piece is located.

Any idea if this is minor surface rust or major issue?
How difficult is it to repair.
I'm mechanically capable, but its been years since iv'e got my hands in automotive.

Looking to restore the truck, and pass it on to my grandson in a couple of years.

The truck appears to be in fairly good conditions, with leaf springs, 396, with aluminum Edelbrock manifold and what appears as a carter AFB carb. It has a turbo 400 tranny and a 12 bolt rear end. Can't find out what gear ratio yet.
I have not purchased the truck yet and will have to travel about 300 miles to go see it. It runs and it's quick. I have many pictures, paint is a little faded, but no dents or dings from what I can see.
I have many questions regarding other stuff I want to do, but I'll save it for later on.

Thank you.
Fabio
U.S.Navy Seabee