cost of visas for a group ( by post)

Hello
I'm planning a trip with some students ( 10 x university age). I want each student to be responsible for applying for their own entry permit. I need to guide them about the total cost. Would I be correct that the entry permit ( type x2) would be £30 and that the postal service fee would be £54 making a total of £84?

is there a cheaper or more efficient way of doing this...i.e a group type entry permit?

Paul