You are buying a digital book. There is a hard copy as well that sells for $250.
The eBook purchase is $150 and good for 24 months.
If you pay $350 you will get the eBook and a Full Color Printed Copy shipped for free to the Lower 48 States.
The retail price of the printed book is $250 plus S/H of $22 and the eBook is $150 for a total of $422. You save $72.