Yep milk sells good. Eggs depends what you sell them with. Since I sell mostly silly crops (soy sells the best in my opinion), it is mostly low level players who will see my add. In fact most if my new followers are around level 10-20. And they buy eggs and wheat full price.
If I placed eggs for sale next to a choco bar only high level players would see me in the paper and the eggs would stay there for longer. Not a big deal: the choco bar sells, egg ad stays so my shop is getting advertised again, I can put new stuff and more people will buy
There is always greg at the end of the day but never happened with eggs recently. Happened with strawberries once.