The subs run from $250 to $350 on Amazon. If you want to amp all of your speakers I would go with a single 5 channel amp like this:
https://www.amazon.com/Alpine-PDX-V9...Cp_89%3AAlpine
You will also need some line out converters of some kind.
I think you could most like get everything for under $1000 including all of the stuff you need for install.
A local shop will of course be a little more expensive.