I spent the last few hours reading forum posts and such, but I figured posting my exact situation would help.
I found an 6spd '04 rx8 with 87k miles for 1500, he said it doesn't start when warm and that you have to wait about 20 Mins for it to start, obviously this is a known issue and is fixable depending on exactly what's wrong. The description also said that he thinks the throttle body needs to be replaced, I'm pretty sure thinks that's what causing the start issue but I figured I'd mention it.
I understand rx8s aren't super reliable used and kind of a money sink, but for me I have a daily driver that is low miles and reliable, so if it breaks down it's not a huge deal, and I just wanted something fun for a second car, and 1500 is a pretty good deal for that. I don't plan on driving it to work every day since I already have a car for that, just want something to drive when I'm going to car meets or to hang out or whenever I feel like it, plus I've always wanted a car I can work on.
Question is, if I go look at it, what should I look for, and overall is it a good idea? I'll attach screenshots of the post.

 

You have some more reading to do.

READ

https://www.rx8club.com/new-member-f...t-here-202454/

^You want to read through this, will answer about all your questions.

The issue the seller lists pretty much describes a compression problem, where once warm the engine is making less compression and hard to start. Trying to start it up again requires it to cool off (and regain some compression to start again). This will require a rebuild which makes this much more than a $1500 car.

This sort of thing is covered in the thread I listed.

 

The engine likely needs to be replaced.
$1500 is about what a good shell goes for, so unless you're willing to spend time and a few thousand dollars, pass.
There are probably a few healthy 8s in your area if you do a search on line to see what they go for.
Unless you get very lucky, you may find a healthy 6 speed for around $5k.
Autos are much cheaper, for good reason.

 

What's wrong is probably that the motor has low compression.

It'll be ~$3000 + freight for a Mazda reman motor. Add in an extra $1000 for incidentals, tools, worn parts, etc. If you aren't capable to replacing the motor yourself, add in at least another $1200 to have somebody else do it (probably more).

You can probably get a rebuild for $2000-$3000 but I can almost guarantee that rebuild will be complete ****.

Regardless of which RX-8 you have your eye on, take it for a test drive to a Mazda dealer and pay them to do a compression test.