Considering a CA King

[Noh]

Hi all! I've been looking into getting my first snake, and one of the snakes I've been considering is a California Kingsnake, as opposed to a Ball Python.

So I've got a few questions about Kingsnakes in particular!

1. I've seen a lot of people use UV lights in their kingsnake's setups. Is this necessary? I've seen a different bunch of people only using the heat pad, and I've also read things by enthusiasts that say UV light is not necessary as long as the snake has a heating pad. I've used UV lights on my plants(yay carnivores!) in the past and while I would use one if necessary, I'd prefer not to because it is a huge hassle.

2. What sort of substrate should I use? I've seen people who say that aspen is bad because it's dry, and others say that sand and dirt are bad because they can get into the snake's mouth and nose. So far what I've gathered is that finely shredded aspen is the best, as it doesn't scratch at the snake's scales and allows them to easily burrow if they want.

3. After the initial investment, how much would it cost to keep one per month? I'd have a little emergency fund set aside for any vet visits or other "surprises" of course.

Thanks for your time!