You can get HID lighting for much less than a comparable LED.
a 315 ceramic metal halide will adequately light a 3x3 and heat is negligible. You can get them for $200 new with bulb. Traditional HID like HPS/Metal Halide is even cheaper especially used.
If you decide on a 4x4 you’ll want a 630 unit, and heat is going to be noticeable in a tiny apartment. LED may be a better option but you’re gonna spend $600+ on an LED to light a 4x4. If you’re in a tiny apartment, a 4x4 full of flowering plants is going to put over a gallon of water per day into the air, which is going to greatly increase humidity in a small space, necessitating a dehumidifier.
Gorilla tents are nice but it’s overkill IMO. Cheap tents do the same thing.
If you live in NYC the market for used equipment is going to be easy. Plenty of options on Craigslist/Offerup/FB market.