I was thinking of picking up some options in a stock that seem...

I was thinking of picking up some options in a stock that seem to be trading at a discount to the shares. It costs 15c to exercise the options., The options are trading at 18c and the shares are trading at 36c so it appears to me that there is a 3 c discount on the options. If I buy the options can I just convert them to shares by paying the 15c and then have made in effect 3c per share or is it more complicated than that. I understand that you get better leverage both on the up and down side but are there any other catches to options trading?

CHeers Russ