First Road Bike

I’m looking to buy my first road bike. I live in CO and typically do ~30 mile rides 3-4 times per week on paved trails. Once or twice a year I want to do bigger 80-110 mile rides with significant elevation gain. I currently ride a trek FX1.

From what I gather I want to prioritize getting a bike with shimano 105 drivetrain. I have an opportunity to buy a 2017 giant contend SL1 in great shape with low mileage for $400 on FB marketplace. It has shimano 105, but I’m a little concerned about the giant conduct hydraulic disk breaks and the fact that it’s an older used bike.

Alternatives I’m looking at are the canyon endurance all road, Trek Domane AL5 or Cannondale Synapse 1 new. The canyon is the only sub $2000 option, but has cues drivetrain as opposed to 105 on the others.

Would love some opinions- should I save money and get the Giant contend or will it only be a matter of time before I want to upgrade? I’d prefer not to break the bank, but want to absolutely love my bike.