If we compare two varieties that are equally demanded, then the productivity of the variety will
affect the price.
For example, Forever Young variety usually costs more than Freedom variety due to the fact that the productivity of Forever Young per m2 per year is below the productivity of Freedom. That is why on the equal areas of the same farm the productivity of Freedom will be higher and it may influence the price.
If you compare a popular variety with a variety that is easy to buy and is in little demand in the market, then a less popular variety will obviously cost cheaper.