My first room built from scratch: 8x12x7 high, studded and plywood(8x8 veg/work area, 4x8 flower) wrapped and sealed in B&W poly, 240v circuit for lights, 2 110v circuits, 2 600s w/cooled hoods for flower, 300w t5 for veg, 256w overdriven t8 for mothers/clones, air pumps, fans, built in sink, rubber lined floors up to 6"(will contain 150+gallon spill, I could empty my res's and not leak outside the room), filtered intake/exhaust air, RO water supply, room plumbed with air lines/manifolds, diy aero rails, a few dwc setups, aero cloner, misc=$3500, appx., I kept all my receipts and added it up, so that's pretty accurate. That's just material costs, took me a couple weeks to build/wire/plumb it by myself.
Sounds like a bunch of money, but it's paid for itself, plus some, in under 12 months. I'm already planning the next expansion.
Probably a few grand spent on outside crops over the years, but they got run alongside my veggie garden, and don't get any real special treatment.