Dobsonians don't need any power, you push the scope around with your hand.
Power is only needed for a cooling fan, but that usually runs off a 12V battery (not 240v power). Not all dobs come with cooling fans, and it's not an essential bit of gear right off the bat. It's something you can upgrade to later on.
If you're looking to get into astrophotography, set your budget at $3k to $5k. If you're not sure yet, then spend significantly less (under $1k) and get a good dobsonian (8, 10 or 12") with a crayford focuser and a few middle-of-the-range eyepieces.
If you really get into it, the money will start flowing on extra accessories after that
