First road bike – older Domane SLR6 deal ($1000) vs newer Emonda/Domane?

Hey everyone, looking for some guidance as I buy my first road bike.

I’ve been riding power zones on a Peloton consistently for about a year and recently went out on a few outdoor rides with friends — and I’m officially hooked. My plan is around ~100 miles per week, with the goal of doing 50–100 mile rides at least once a month. As much as I enjoy Peloton, long rides staring at a screen just aren’t it anymore.

I’ve test-ridden both the Trek Émonda and Domane, and honestly liked both:

• The Émonda felt lighter and snappier, which was a blast.
• The Domane felt more comfortable and forgiving, which seems better suited for the longer rides I want to do.

Because of that, I’ve been leaning Domane, though I’m not completely opposed to an Émonda ALR.

Here’s where I’m torn:

I found a 2018 Trek Domane SLR 6 with:

• Roval Rapide CLX rim brake wheelset
• Ultegra groupset
• Garmin Edge 530
• Some additional accessories thrown in (see pictures)

Seller is asking $1,000 for everything.

That seems like a solid deal, but I’m unsure how it stacks up against going newer. For comparison:

• New Émonda ALR is currently on sale locally for $1,999
• Also considering a newer-gen (2022+) Domane SL

This will be my first road bike, and I’m hoping for something that:

• Can handle comfortable century rides
• Could potentially be used for triathlons in the near future

I know this is a lot to compare, but I’d really appreciate input from those with more experience — especially thoughts on older high-end carbon vs newer aluminum/carbon, comfort over long distances, and whether that 2018 Domane deal is too good to pass up.

Thanks in advance!

TLDR; New road cyclist coming from Peloton, planning ~100 miles/week and monthly 50–100 mile rides. Torn between Trek Émonda vs Domane after test rides. Found a 2018 Domane SLR6 w/ Ultegra, Roval Rapide CLX rim brakes + Garmin 530 for $1,000. Unsure if that’s a great value or if I should spend more on a newer-gen Émonda ALR ($1,999) or Domane SL (2022+). Looking for advice on comfort, long rides, and older high-end vs newer bikes.