REPAIR DETAILS

I want to buy this van but I don't know the first things about if it's worth it mechanically or not. It is a 1991 Ford Ecoline. The odometer says 22,000 miles, but the seller did say 122k. The main things I noticed while driving it was that 1- when I was breaking on a curv after the highway exit I felt a light thumping under my feet. 2- you have to turn on the overdrive once you get to 55mph 3- it like sputters??? When it turns on, and when you turn on the overdrive. Not sure if that's just an old van thing or a bigger issue 4- she said the battery died yesterday but she was able to recharge it up. 5- decent amount of like outer cosmetic rust that I don't think is actually a huge issue. I am expecting to need to put a decent amount of work on the vehicle especially since it is so old. But I would really like to know if it is worth it or not. I need to know if it's worth the asking price ($3,000) and a diagnosis of whatever needs fixed and an estimate of fixing each thing.