Okay Just to confirm based on Adrienne
I got on the DBBahn site
I can purchase 4 tickets for a total of 76E
This will cover a bus ride of 3hr and 37 min to the train station in Prague (I think bus # 1053)This price I believe includes a seat reservation (If I chose salon)
I can purcahse 92 days ahead.
Am I correct that this is cheaper than buying them at the station?

It will be cheaper to buy in advance. When all the discounted tickets have been sold you will have to pay full price. Of course, it is possibly that if you wait there may be some discounted tickets available at the station but you will take a chance if you wait. It's a difference of E29 per ticket. I would not wait to buy if you know that you will definitely make the trip.