Small tattoo VS. big tattoo. Is there a difference?

I currently have 2 tattoos. One on my upper arm/shoulder and a small tatt on my forearm. That one is obviously visible when I wear short sleeves. I'm in collections and make $60k a year. My tattoo has never been an issue. I've recently became fond of Japanese art-specifically koi fish and dragons. I was thinking of getting my whole arm tattooed with one big Japanese style tattoo. Since I already have a small visible tattoo ALREADY,do you guys think it will make a difference if i get a bigger tattoo? If I'm out for a job interview I can always cover them up-and continue to do so if need be. I am also aware that tattoos might not look good when I'm 80 but I'm not gonna be at the bar picking up chicks at that age either. I'll be bald,wearing dentures and probably have poop in my pants so a blurry tatt will be the least of my worries. What do you guys think? Should I go all out?