This has become a challenge for many of us realtors. Most buyers don't understand that these sites aren't as polished as they need to be for buyers to rely on them 100%
It is going to be up to your realtor to educate buyers about the use of website for evaulation AND for him/her to provide them with a real time evaluation of her own to prove her point.
Good Luck . . . I share in your frustration.