Uncirculated Commemorative

What are more valuable; proofs or uncirculated, or commemorative?

I am a Viet Nam vet. Took my son to see the traveling wall about 7 years ago. He’s in the service and that visit to the wall meant a lot to me. I want to get him the viet nam $1 silver coin. There is also a 3 coin set out there w/the coin I want, the POW $1 (which also means a lot) plus the female service $1. I see $99 to $159. Some say proof, some say uncirculated. I want the coin for my son, but I also don’t want to get ripped off. Being a disabled vet on limited income I try to watch how I spend. Any assistance would be appreciated. I need to get these ordered and in the mail. I am kind of on a time schedule. Appreciate any and all help!

I don’t know about that specific set, but in standard coin collecting.
Proof is the highest grade, it is usually double struck for better quality
Uncirculated means that it has not been used
Commemorative just means that the design is a special one.

Coin Collection