I want a pet that's easy to look after and cheap?

You should tell your mom all about the animal you will be thinking of caring for EVERYTHING look up all info on the animal when your mom asks a question you will be able to answer the question with complete convince. What it eats what it does at night how it acts around humans how will it adapt to the new home so on and so on if mom asks the question you have a stable and very informed answer.Tell mom where it stems from what it eats how it lives its life cycle the rate of growth its type of foods it eats How it reacts to captivity and people.

Inform your parents of the animals diet, weight, type (either a mammal reptile so on and so on) housing, diseases, foods, grooming, social life (if any) behavior. so on and so on get all the info you can and inform your parents that you have done your homework and not rushing into a pet without knowing what the animal requires to be a well kept animal. Be sure you will be able to provide the necessary foods for the pet you decide on and you can supply the needs for such an animal. Make sure you have enough time for an animal and Love to give an animal as well.

Sugar glider, Bunnie, bird, hedgehog, chinchilla, snails,fish,snake,lobster, crawdads, salamander, baby lizard,mouse,rat hermit crabs

Ok, no pet is cheap. You need to pay for food, water, home, ect.. If you want the pat itself to be cheap go to a shelter. They have lower prices since they want to get them to a nice home. I don't know about a mouse but he might be at least that amount.

So to show your Mom you are responsible you should do a presentation. That is what I did to get my rabbit. You should be willing to pay for it. It will help convince her and not go on about wasting money. Do A LOT OF RESEARCh. Show her your grades or make a commitment.

I'd get a rabbit. I have 3 and they're so loving! Get a baby one though so you can bring it up the way you want it to be :)

a fish

You should get a rodent of some kind.