Can you tease out the parts befor you buy them and are the reasonable prices. I am single mom who has a Jeep library 2004 and the window are duck taped up. So I need to take to doors off first to see what I need

If you look on line you can find ways to test in the yard with a power tool battery. They do have a replacement only warranty for 30 days if you hear the motor run it is probably not the motor but "strip" or regulator

Is it both windows or just 1?

Replacing door window can get a lil messy, if this be your first time ... & if they r power windows than u will need those zipper tracks also .... Have fun

No. You can inspect parts but not test in most cases. They have great prices. 50% off sale following every holiday