Hand-painted ceramic tiles can be very expensive and the reason is simple, it takes for ever to hand paint ceramic tiles. This is hard work but can look amazing when used in combination with regular tiles. If you are interested in unique ceramic tiles you should at least consider that.
Please note that hand-painted ceramic tiles cannot give you the same precision as when painting on a piece of paper. You cannot get a high quality portrait done on ceramic tiles for example. You can put some artistic figures on it and it usually ends up looking great. I personally would not for for hand-painted tiles, but in the end it is all about what you need it for and how it will look in that specific place.
You can of course put hand-painted ceramic tiles on walls and floors but you need to make sure that ceramic tiles you paint on are appropriate for the surface you’re going to use them on.
There are many companies that are in the hand-painted ceramics business but as said they can be quite steep.