The bike looks pretty nice in the picture. I find this trepidation over used bikes is often overblown. True you can buy someone else's problems. But if it looks pretty nice or unused, and you feel pretty good about it, you often get a barely used machine. It isn't modern, it is pretty decent quality. I do think the price is too much. Probably half would be good, certainly I would top out at $200 if it looks exceptional in person.

I think you have to remember what a starter bike is. Someone starting doesn't know what they want exactly. Getting a good quality, older, affordable bike of the right size pretty much is all you can hope for. This appears to qualify.

If you owned this bike from now on, and it fits, you haven't done badly. If you are fully smitten by road biking, you will grow and refine your tastes, and needs in the future. This bike if fully capable of getting you there also.

I would caution you to be patient. Keep looking, and something very nice and affordable will turn up in a few weeks or few months.