I think so, if you’re really concerned about your oral health. I have the Oral-B Triumph, a $160 toothbrush, and I absolutely love it. I used to have a Sonicare, which is also supposed to be very good, and I got it for free from my oral surgeon (I’m sure it’d be usually around $100 or more) when he found out I had been using a manual toothbrush. It was very good, but it didn’t clean the inside of my teeth as week as the Triumph does.
Then again, I have a different situation with my teeth than most people. I have two implanted teeth (ceramic crowns attached to metal rods implanted into my gums) and four of my teeth have almost no root due to complications with my braces. So, the health of my teeth and gums is very, very important—otherwise I might lose my teeth and waste thousands of dollars worth of oral care.
But oral heath is important for the average person, too. Having healthy gums helps prevent getting sick (viruses and bacteria can easily enter the body through inflamed gums), and of course you have nicer looking and feeling teeth. Chances are your $25 rechargeable will do a decent job, at least a lot better than a manual toothbrush. Some Oral-B models, even the cheaper ones, can use the nice heads that usually come with the more expensive models. However, heads themselves are expensive – about $30 for a pack of two.