I've just bought a new one to replace my old one Hannah. I always use cordless ones now and it depends how much you'll use it. A corded one will usually be cheaper -probably around thirty pounds (?) - but you'll need an extension cable if you want to use it outdoors. I have a Black and Decker corded one which I've had for well over twenty years but I use it less now for that reason.
My new cordless is a Bosch. It was about £60, two batteries and 18v, but you can get them much cheaper if you only want one battery and less powerful. It's not too heavy either which is important for me. I've had cordless Black and Deckers before that. I'd avoid own brand ones and go for something reasonably well known. For plastic pots you can use screwdrivers or similar to make holes but I use a spade bit on the drill for a neater job and to get the holes a decent size. Most clay and glazed pots already have holes but if you have metal containers you can use a masonry drill bit to make holes. Hope that's of some help.