Trek Domane SL 5 – Is this a good deal? + sizing question?

This bike is being sold used by a local shop (not on marketplace). At this point, i don't know anything about the condition, materials, or components of the bike but wanted to know if this is generally a good price for this model assuming its in good condition? I am looking to potentially upgrade from my hybrid and have read that the domane is a good option for both road and gravel which would be ideal for me. To be honest though, i'm definitely not super knowledgeable about this stuff yet so am just trying to get input to not get ripped off.

Separately, I am 5 ft 2 and looking at trek's website it looks like 50 cm would fit me although obviously i know i would need to try it to make sure. its very difficult for me to find pre-owned bikes in my size so options are definitely limited. I would be curious if any other women my height have experience with this particular bike/size?