Is this a good deal?

Should be a good size for you.
What groupset/rear derailleur?

It’s it’s 105 I think $200 is fair.
If it’s dura ace/ultegea that fair.
Anything below tiagea, I’ll say how’s $150?

I personally like the triple, usually lower gear and I like climbing, and I don’t like the big jump between gears of the modern day day 1x.