Changing color of the car is expensive, in the multiple thousands, even for cheap paint. The reason is that they paint the area under the gaps. So, they need to paint under the hood, trunk lid, and doors. If they didn't, your car would look weird. If you keep it the same color, they will just tape over the glass, plastic and rubber pieces and spray paint the body, no need to paint in the gaps.
I've had cars repaired where only some body panels were painted and they charged thousands of dollars. It wasn't even the whole car.
Call around your local body shops. They can give you a ball park figure better than anyone here. Forget about using House of Kolor paint, doesn't sound like you have the cash for that.
Things that can lower the price.
1. No body work needed, like filling dents and dings, rust repair, etc.
2. Use a popular color, gloss black. Not going with something expensive like pearl or metallic finishes.
3. Prep the surface yourself. Fix dings, bondo and sand the surface yourself.
4. Find a person, not a business, who paints cars for less. You may be able to buy a can of car paint (this is quite expensive) that is fancy for less on eBay and then give that to the dude to use.