I'd say you're right to be wary. Did all you have previously was a verbal agreement that your actual rent would be discounted to 2475? If so, that's very sketchy - that's a smart move to have the lease re-written to reflect the agreed upon actual rental amount.
More often than not it pays to trust your gut on this (in my opinion anyway, I tend to be overly paranoid though
). If you really, really have your heart set on that particular place, I'm sure you could get a lawyer at a reasonable fee to look over the revised lease.