I currently own a 27" iMac with a Magic Mouse and Apple wireless keyboard, and am finding that I have to replace the batteries about once a month. Once every few months, I find myself having to go to a store to buy another pack of batteries (the price is around $7 per pack). The Apple rechargeable batteries are $29. Do you think I should buy it? The Apple keyboard and mouse are the most frequent items I have that I have to replace the batteries for. I think it would be better on the environment and on my wallet in the long run if I bought them. What do you think? Thanks.