If you are doing the work yourself, you can expect to spend between a few dollars and several hundred - it really depends on what is wrong, and so far, we do not have enough information to say.

What happened when you tried to jump start the car?

What kind of battery charger did you use, and how long did the charging take?

I ask because it still sounds most like a weak battery is causing your problems, which would indicate a charging system problem, since it is new.

Simple stuff first.

A simple test for the battery, without any test equipment, is to swap with another car. It's free, and doesn't take long. If the car still doesn't start, we have ruled out the battery. If the car does start with a fully charged battery from another car, your alternator is next suspect.