I know the mid series have beiging but if you hold out you may find a nice set. I did and it's almost perfect. I did buy a set and then pick cards to enhance my set. It's tough to buy a perfect series set because they may be beiged but also if you have a prestine series 6 it might not pull in big dollars. It sucks as a seller so why bother. This also hurts the uneducated buyer because they think all mid series should be cheap. It's a slippery slope with mid series.
I,personally, think if you find a solid mid series for a higher price you are getting what you paid for. I think those sets should sell close to $100 but the masses are trained not to pay much so as a seller why bother.