Vintage T-Shirt Forum & Community Authentication Appraisals

Received this shirt from a friends uncle who said he got it at the show. We live in Dallas and I can confirm he was there. The shirt does not have a tag but is in really good condition any info would be awesome thanks so much.
Also if anyone has a guess on what they think the value would be that would be much appreciated.

Beauty, legit, ZZ Top is a bit of a weird one, not many of their tees are worth a ton of $$. This one, because of the size, 80s, limits those who can wear them too - and not everyone likes the jersey style. Would put it at $75-100.