Not really. Looking at it, they want rent for the earlier of 3 months or until re-rented, plus a Realtor commission. The only thing I'd question is whether they paid the Realtor commission when you originally moved in, either in part or full. If you had to pay it (1st, last, deposit, plus Realtor fee or usually 1 month), then that is a bogus amount to tack on since they will basically double-dip (charge you the Realtor fee, plus charge the next guy the fee). If you didn't pay it, then again that is fair -- the landlord ate the commission to secure 1 year of rent, if you are reneging then it isn't fair for him to have had to pay a 1 month fee for only a few months of you being there when he could otherwise force you to adhere to the lease and pay for the full year.
To be honest, 3 months or until re-rented isn't too much to expect. It can take a while to find a new tenant and it isn't fair to the landlord to have to eat that risk by himself. Plus it isn't like he's charging a full 3 months as a fee -- if it rents earlier he stops requiring you to pay the rent the new tenant is paying.
If you want to do yourself any favors, blast the rental listing around to any friends or communities you know. If one of them rents it out quick enough, you'll avoid some of those 3 months of rent for nothing payments.
EDIT; He also basically has you over a barrel. If he wanted to be an ass, he could say "too bad you're moving...continue paying me for the remaining 7 months whether or not you're living there" and be perfectly justified in doing so. Of course, you hold the trump card of being able to not pay and force him to evict, take you to court, etc. Most landlords don't take legal action other than to evict because deadbeat renters are usually deadbeat because they have no money to win in a judgement. But if you're willing to run that risk that he could take you to court and win the 7 months rent plus damages than go ahead, that's legal to do. I'd say it's unethical, but so is walking away from underwater mortgages, and people do it every day and then complain the IRS taxes them on the forgiven loan.