I don't know if age is as useful as something like list of projects, publications, or contributions. Something to denote saying "yes - this guy has been down the path I have and released it's a dead end" rather than just spewing what he learned in class or some random article on the internet.

Someone laughed at me on reddit when I told them you didn't need a lot of money to make a good game (as you can outsource if you need to - trust me there is someone in India who is willing to create that sprite sheet for less than $20 versus your artist friend would charge $200+). They claimed you needed like $X million. An obvious counter-example would be Terraria - I know not everyone likes it but I think it's a pretty successful and well put together game. It was made by 2 guys sitting in a home office somewhere. I asked him how many games he worked on - I believe he responded with, if I remember correctly, 3.