BK 86 - payment for impermanent damage

The Gemara brings the argument between Rava and Abaye as to the obligation where one has caused an impermanent damage. Abaye says the damager pays 'sheves gedolah,' the value of the hand, and 'sheves ketana,' the loss of work as a cabbage patch guard. Rava says there is no payment for the hand, rather he is paid for his loss of work, but his work as a regular full-fledged worker.

I was wondering why according to Abaye one would have to pay for the hand if it is going to return to full usage later. I realized that the payment will be the difference between what he was worth before the damage, and what he would be worth now if he was sold as a slave. If he was currently sold, the person buying would be aware that his new slave's hand would be returning to full use soon, so the market value of the one damaged has not gone down as much as if he had lost the use of his hand completely.

It is also important to note that both according to Rava and Abaye, the value of the hand is being paid for, however, it is really just a question of how we look at the temporary devaluation - as נזק - the regular damage, and therefore we look at the slave value (Abaye); or as שבת - the loss of work, and therefore we look at his full loss of work (Rava).