Here's my first large space station, only just completed after being built over a span of ten irl months. It was built in 100% stock, hardcore career (no flight resets) using realistically sized rockets.
Specs:
Parts: 251
Mass: 111.8 tons (no fuel or asteroids added)
Size: 20.9X29.4X45.2
Cost: $284,000 (more than $2 mil to put into orbit)
Orbit: 200x200km, equatorial
Frames while in physics range: <2