Vegan or not?

A friend of my friend recently, in the last year has become a very serious veganER.... to quite an extreme extent he has loss a tremendous amount of weight. Our friend's father is a GP and insisted for him to get a thorough health check since he's lost that much weight. A little while back his test results came back and he is in top notch health, with the cleanest, most functional colon...
AND to top it off, radiant skin!!
However, down perk to it all (aside from the actual diet itself) is the cost.....

Being a momi of two I am constantly searching for that moderation which will best suit me. My main concern/goal is to be healthy, yet slender however still enjoying life...
This all wraps up to be a part of my vanity insanity.