Used bikes plus any advice you want to give

[Wasabispice]

Hello, I am new to this site. I have been commuting 4 days per week, about 5 miles one way for a while now. About 6 months ago I started at one day a week and have worked up to 4. My route is almost all road and several big hills. I have a heavy, cheap mountain bike (think Walmart). I am finding that after 4 days of riding my legs are done, which is why I haven’t increased to 5 days yet.

I am a pretty fit person, no athlete, but participate in many outdoor activities and exercise most days of the week. My long term goal is to commute every day for work, going to the gym on my way to work. So ideally, my commute would be more of a warm up, then I can workout.

I have been watching my local classifieds to find a used bike. A friend of mine recommended a road bike, but I am wondering if a hybrid would be good, especially if I later upgrade tires. One of my biggest worries is weight, I think because my current bike is so heavy.

Here is one bike I found, does it seem like a good deal (assuming good shape and fit)? https://classifieds.ksl.com/listing/57362688

I also found this bike online through a bike shop that has a couple locations near me:
https://contenderbicycles.com/product/trek-2300-trade-in-size-sm/

Any advice or thoughts?

Summary: I want to commute more, hilly area, roads mostly, do these bikes look good?

[Painkiller]

both are nice bikes. The Vita is in the sport fitness class and the trek is a mid level road bike. The Vita is Specialized womens version of the Sirrus. I just picked up a 2015 Vita for my wife and she loves it. Fully capable of touring and commuting because of the mount bosses on the forks and rear triangle for baskets or racks and bags. Flat bar sport bikes are great for this and can be geared faster much cheaper down the road if you wanted to do that.