I do not feed raw anymore (paranoid family) but I'll give you my experiences and what I know about it
How time consuming is it?
In my opinion... it really doesn't take any more time than it takes to scoop out kibble. In some respects it depends on your dog, Juno is a gulper and so I would have to hold her food to make sure she chewed it, and even after being on raw for a month she STILL didn't learn to just chew the stupid thing on her own lol. Most dogs are not like this, and you can just hand them a chicken quarter and go on with your business. But even having to hold Juno's food, it would take her less than 5 minutes to eat so it certainly wasn't a big ordeal having to do that for her.
The most time consuming part is when you turn your kitchen into a butcher shop after you've gone shopping for meat.

You figure out your own system for how you want to organize and store things, but for me, as soon as I'd get home from the store I'd take all the meat out and cut it to an appropriate size, and put everything in labeled Ziploc bags (one bag for chicken quarters, one for chicken wings, one for pork ribs etc etc). Depending no how much meat you can store though and how often you go shopping, this might be something you only need to do, say, once a month. And I'm a weirdo and thought it was fun.
How much better is it for them than kibble?
Way. I believe that dogs are carnivores and a raw diet is what they were made to eat--so in my opinion even the very, very best kibble on the market is nothing compared to a raw diet. You know exactly what your dog is eating, no ambiguous ingredients or unnecessary things added. When you feed your dog chicken, it really is chicken and it's the exact same stuff you prepare for yourself for dinner. The dental benefits are amazing, bones are nature's toothbrush! Their coat usually becomes shinier, they shed less, and don't get much of a dog odor. And the poop--OH, the POOP! They are tiny and odorless and turn into a white powder after a couple days. This is because everything they are eating is highly digestible and their body is actually using it. I miss Juno's raw poops.
Our biggest benefit of raw was that it actually helped Juno's incontinence. Raw fed dogs typically don't drink much water, because there is a lot of water in raw meat. And so since she was drinking less (A LOT less), I suppose that meant she wasn't keeping anything in her bladder to leak out. It was nice.
What does it cost in conparison? I live in the mountains and everything costs more here because its hard to get it to us so this is a big concern for me.
Well for me it was more expensive because we use Costco kibble, which is like $30 a month. But it was cheaper than most high quality kibble. I think I probably would have been able to stay in the $30-$40 a month range. In the beginning I think it is more expensive, because you have to introduce each protein source one at a time--so if your dog is only eating chicken and turkey, you can't just wait for it to go on sale. But when your dog is a seasoned raw eater and you can feed them anything under the sun, then you have the ability to wait for a pork sale, because your dog doesn't NEED pork if you have other meats in the freezer to feed. If that makes sense? It's also cheaper if you have the space to buy in bulk and have a supplier to order from, versus purchasing at the grocery store. I tried not to spend more than $1/lb on things if I could help it.
What are the benefits of RAW vs. Kibble?
I think I touched on that a bit in the "how much better is it" question. Here's a list though:
Benefits | Prey Model Raw (that whole website is good!)
If I were to change them to RAW would I do it liek I was changing their dog food? Slowly and mix the RAW with their kibble?
It can be a little complex here. Don't feed raw and kibble together--kibble digests much more slooooowly than raw does, and if they are fed together the kibble will keep the raw "held up" in the digestive tract, and that's when bacteria can start growing (this is the reason why dogs don't have issues with salmonella etc from eating raw meat--their digestive tracts are short and raw moves through so quickly, bacteria doesn't get the time to grow). You are better off switching to raw cold turkey (no pun intended

), or if you have a bag of kibble you need to finish off, then do a raw meal in the AM and a kibble meal in the PM or vice versa.
This is a really good guide on how to transition a dog to raw--I would follow it to a T:
How to Get Started | Prey Model Raw
A raw diet looks SO COMPLICATED when you read about it. So many numbers, percentages etc. Let me tell you, don't let that scare you off. It scared me off for so long, I thought I'd screw up and not feed the right things or not provide all the nutrients that were needed... but once you actually start doing it, it is way easier than it sounds.
Feel free to ask whatever questions you come up with!!