The main tax benefit of options is that you don't have to pay taxes until you exercise them (convert them into real stock). So even if you get the options at a

The main tax benefit of options is that you don't have to pay taxes until you exercise them (convert them into real stock). So even if you get the options at a discount then you don't have to pay until you want to convert them / cash them in (i.e. cost to exercise is $15 and the value per share when they are granted is $20).