Unrepentent record collector for 30+ years, worked at a record store in Seattle during the boom ('88-'97). But... I am not super picky in terms of audiophile stuff.
A good turntable with a good stylus is essential, however, if you give a $hit about your records. And knowing how to weight the stylus is important, as is being able to adjust the tracking -- many people set it waaaay to heavy which ruins the records, and a turntable without decent tracking will also wear records. The Crosley vintage-looking turntables are crap, as are most of the "convert your vinyl to digital!" one-piece set-ups.
I have 4 technics 1200s -- one to listen to, 2 to DJ, and one spare (that needs some work). Some audiophiles complain about noise from the direct drive, but I don't hear it. That being said, looks like the guy is selling belt drive tables. Good to ask about the availability of replacement belts.
And I was like Ekpent -- bought stuff at garage sales (never paid more than $200 for my Technics, and now they are big bucks). Had a few tube amp receivers, but I don't have one now. There are modern tube amps that are worth having, but nowadays they are charging an arm and leg for them. It's still possible to find old ones used, but less and less so.
I've used several different things to digitize my records, including a great Sony CD burner that I bought new when it came out. When it died, I bought a few used ones that lasted a year or two -- but since it was discontinued I decided I needed something else. Bought a fono mini A2D pre-amp, which digitizes analog and plugs into a laptop. Audacity is an open source program that allows you to manage the digitized content, turn it to MP3s, and upload to a phone. If you care about digitization.
I know I'm rambling, but to get to your questions: Don't buy a cheap and crappy turntable. Both the NYT and Discogs have published turntable buying guides, and IIRC $300 is kind of the bottom end -- but it may be possible to buy something worthwhile. For me, I change needles every 6-12 months depending on how much I am playing records; a solid needle is super important to me. I bought a bunch of the Shure styluses I like when they went out of business, but I'm going to run out and have to figure out what I use next. One thing to take note of is that not all cartridges and styluses are compatible with all headshells. Might be worth asking about for the turntables, as well as stylus availability and price.
For the speakers, I also think the Sansui SP-1500s look like a killer deal -- as long as all of the internals are intact. And it'd be cool to pair it with the Sansui receiver.
But make sure the turntable and needle are solid if you care about your records lasting.
