I'm a sonicare fan, but you have to pick a tool that doesn't frighten you and for which the replacement brushes (expensive) are not TOO expensive. If you don't replace them, they don't clean! You might try buying the absolute cheapest Sonicare at Walgreens (my area of residence ..... ) and then if you see you want more bells and whistles (like 30-second timers, or sounds, or whatever, throw it away and buy the fancy one.
But all rechargeable batteries eventually fail. Read that sentence again.
On this newsboard, I also suggest that you get a good light and read the nameplate of the CHARGER. My cheapo Sonicare ONLY works on 120 Volts, so I have to carry a small transformer when traveling. I already own it, so there was no expense involved. This transformer is too small to run a big appliance, so it's not a big deal. But they may not be widely available. And I've already ruined one charger because I got careless in Europe. But every time your battery wears out, you have to buy a new unit, which comes with a charger.