A box is gonna cost you around 200-250. That's shipped and whatnot. Are you going to be doing your own wiring or having a shop do it? And if you keep the power to around 1000-1500 an amp is going to cost you in the neighborhood of 150-250 depending on what you're getting. Still leaves a lot of room in the budget for subs.Still need to buy an amp. wiring, have a box built and the 4 subs.an anything else need