Relative premiums on options

Friday morning I was poking around the options chains and noticed that the GNK 22.50 July Puts (which were slightly out of the money) were trading at $1.20. What that means to me is that a lot of people were betting that the stock would go down since they were willing to pay substantially over $1 for an option that was still not in the money. So I went over and looked at the EXM options chain and noticed that the slightly out of the money July $7 Puts were only trading for $0.50. Huh? Since the sector usually has large swings and tends to trade together... there appeared to be an opportunity here. So I snapped up a bunch of EXM $7 Puts at $0.50. Again, since I do not have the ability to follow the market every moment, I put in a Limit sale at $0.80 to lock in a 60% gain ($0.30/$0.50). We will see how they perform today (Monday)...so far so good.

Update: Apparently somewhere around 11am (Eastern) it sold for $0.80. Nice.

To further the point of the dispairity (as of 5 mins ago - and forgive the crude formatting):

Stock____Price_____Strike____Put Price__Comment

EXM____$6.98_____$7.00____$0.80____In the money by 0.3% but 20% discount

GNK____$21.65____$21.00___$1.45_____Out of the money by 3.1% but 45% premium