I'll add here that perhaps our expectations are the reason we see this different. Even if you guarantee that heads trade at 5c in 12 months time, I would expect the oppies to trade a little higher than you have stated (it does depend on what the expectations for the company over that next 12 months is then, which cannot be known today, as the oppies still have not far off 2 years to run from today).
Should the company get from 5 to 10c from 12 to 24 months from now, the leverage on the oppies at prices you have stated is still very substantial. I am anticipating around 10c on heads in 12months time, but realise this involves things going to plan, which for many reasons may not eventuate. This is the speculative end of the market after all, not much is certain.
There will always be people willing to take a punt at levels such as what you have stated above. For example if it doesn't work out, they convert the oppies at a small loss as they are nearly in the money anyway, best case heads rise nicely and oppies holders make several hundred %.
It's simply about our own individual expectations, investment strategies and risk appetites. I was more than happy to pay 0.7c for my oppies and will look to add if they drop to 0.5c, you may not be as bullish as me here, which would be the obvious explanation why we see it differently. After all, it would be a very boring market if we all acted the same way.