Hello /n/

/biz/ here, first time posting here
tl;dr: I'm currently a fatass (5'11 250lbs) and looking forward to buy a bike but I don't know shit about bikes (last time I had one I was a child)
I went to a store yesterday and the cheapest one they had was $750, which surprised me so I started to look at used bikes in my area
Those are 3 available right now, but I'm not sure which one I should get. I'm basically looking for a bulletproof bike that doesnt ride like shit or breaks all the time since the roads are full of potholes here and I'm a big guy
the bike would basically only be used to commute back and forth to the gym daily, which is 2.5km away
any general thoughts/comments are welcome

thanks frens