Of course private deal rocks only genuinely private deals. Sadly duz has become dealer's backyard: who call you 20 times a day for asking "last cash price" and offer 50% of the advertised price.
I agree with annie, but still if someone is in rush and have no time for viewing then I feel Al futtaim automall, dynatrade and 4x4 motors are kind of fair evaluater and offer almost 80% of the current market value. I have sold my 2 cars that way in past when I was in real rush to get a parking spot for my new car.
Get to the good tire shop and ask them to feel all 4 tire base with bare hand thoroughly to find some bump, I am more than sure if alignment and balancing is fine then this noise (especially thumping noise) comes due to swollen tire. This is very known storage defects and can be considered under manufacturing defects if you have receipt of tires from where you purchase them, they should be replacing this free of cost.