I think the $2.05's trade less than the $4.50's because they are a worse deal. The two break even at a share price of $8.15 (assuming the $2.00 and $1.20 prices posited), and a good top line followed by a good RRR% will put the stock much higher.

The advantage of the $4.50's grows as the shapre price rises. At $15.00, for example, the $4.50's are ~35% better than the $2.05's.