I was being very generous (good microscope, high-end Oki heat gun and soldering iron which professionals would use).
Chinese imports are at the $100 range for the gun and iron. Microscope, probably not unless you can get by with a USB microscope of some form. Although, you can get by with the same stuff that jewelers use (glasses, loupes, etc.)
And, I'm sorry, but good tools for doing anything cost actual money. Anvils, sledgehammers, etc. all cost near $50+ or so.
However, you are significantly underestimating the cost to hack on an Apple II. First, the Apple II was damn expensive--it was almost the price of a new CAR. Chips were way more expensive, and you needed a lot more of them. Edge connector cards and edge connectors were very expensive.
There was a reason why so many people loved the TRS-80 Color Computer for robotics and control applications for many years. It had analog ports you could get at with inexpensive connectors and the connector on the side had almost every digital signal and wasn't ferociously expensive (although, it wasn't cheap. IIRC, prototyping cards for it were in the $70 range in 1981).
Things are WAY better now for the hobbyist even with surface mount technology.
Skill, yes. Expensive? Define that. A microscope, a heat gun, and a soldering iron total to about $3,000 for quite good ones.