Help kitten Monty see the vet

I've never done this before. I've been blessed enough to never have to but I guess everyone struggles eventually. Yesterday my mom found this little kitten in the warehouse at biglots while working. I have two cats already (one of which was a stray kitten who was sick and in desperate need of care and now healthy happy and fat.) So thinking we could care for him and give him a forever home, my mom brought him home. He's sicker than we thought and we're so broke right now. He needs to see a vet as soon as possible but we can't afford it right now. I'm asking for 100 dollars to get Monty the best care. He is very skinny and can't keep food in. His paws have sores on them and he's covered in fleas. Any money left over will be donated to a charity that helps strays like Monty. Please help us out if you can.