I had a 40 breeder reef in college and I think it cost me around $500 before corals and fish. I bought used equipment and I bought cheap fish and bought corals off locals and not overpriced online venders. I did go with all dry rock though due to budget and had to go through the uglies.
Even my 80g I have now wasn’t that bad because I bought used gear, a 4 foot 6 bulb ATI used was $200, my regal skimmer was $100 and so on… a fraction of the price of new and they work just fine.
My expensive part is probably my fish

While I am too cheap to buy a new skimmer, I can easily blow a few 100 on a fish.