power steering pump

Hey, so in my 06 Aveo5 my power steering pump is going. Its been going since the start of December, haha. Basically I had a seperntine belt snap, whenever they put on the new belt it ended up slicing through the hose which caused all the fluid to leak and basically just run through the pump towards the house and all over wherever I was. They replaced the hoses and filled up my resevoir complimentary but claim I said I put fluid In myself and aren't covering the work because apparently I put in a wrong kind of fluid which ruined my pump. Anyway, I've got two questions..

How much is a new pump?

How much should a used one cost from a junk yard and what model cars could I take one off? I'm assuming Pontiac Wave and Suzuki Swift!

I would only buy a new one, they should be about $100 or less new at the auto parts stores.

Ebay is another option for a new one as well.

new or used/reman doesnt matter too too much. get what you can afford and get it with a warranty.

are you putting it in yourself?

Alright, I guess I'll save the $50 and get a used pump and nope my friends dad offered to put it in, he's a mechanic well retired one now but he has all the tools at home. Just flush out the system, disconnect the hoses, take off the drive belt/fan belt, unbolt the pump, put the new pump on, put the drive/fan belt on and then connect the hoses, right? After that fill up the resevoir with the fluid then turn on the car and steer the wheel dry from left lock to right lock about 10 times each way? That's what I was planning on doing, he's gonna watch me do it but I kind of want to give it a go on my own.

as you add fluid, turn the pulley on the pump by hand, it will help eliminate air bubbles, before trying to do it by turning the wheel (if the pump allows you to turn it by hand)

Should I do this with the car on or off?

Got a used pump in town today off a Pontiac Wave that fits my car, $86 taxes in and came unbolted all set to go, took about 5 minutes for them to get it off the shelf and on the counter. Also comes with a 30-Day warranty, which allows me to install myself so I don't need to argue with an online store or seller off eBay or even deal with a big corporate place like Canadian Tire. I think it's for the better, getting it installed Saturday, I'll post up the results when it's done.