Active monitors run directly off of your laptop. Simple, inexpensive, wonderful, done! For example, I outfitted my office with a pair of Adam F7 monitors ($900) connected directly to my laptop headphone output with inexpensive cable. Adam makes a sub specifically for their F7 monitors, though I've yet to feel the need for it - satisfied 95% of the time thus far without it. Had I more coin to splurge on audio I'd consider the sub and perhaps a USB DAC as well. But very satisfied thus far with just the monitors.
$1500 for a whole system, budding audiophile
Just imagine you're in high school now. You're going to budget $1500 on Amplification, speakers, and a source/ sources. Where do you spend your money to get you through college and an entry level job? Let's assume you have the computer covered and not include cables or headphones in the budget. New? Vintage? Mix of both?