When I was kid (11 year old) and I start to buy models, yes, the box art played a big role on buy the kit. Expecially because I buid different airplane and other military vehicle. They had great box art, expecially the one during combats, or war zone, that make you imagination fly! After few kits, I realized that the box art was different that what was inside the box. Like when I built (1990 ca) a Italeri F-8 Crusader, and it was all white, I know that I could painted it, but a that time paint, and painting a model was a futuristic things...
After that, I just look for the subject, no a the box art. I need to admit that there are some cool box art around. I have some old kit, and when I build them I will keep teh box, because personally I like old stuff.