If you are indeed up for learning to do some basic mechanical work, you could probably buy a nice '90s hybrid bike and set it up with skinny tires and full commuter gear for less than the price of the Nashbar bike. That's what I'd do. Honestly, if you were covering the 3 miles on bikeshare, you could probably do it on any vintage bike -- a Raleigh Sports can be a great commuter, for instance. Bikes from the '60s-'80s are cheaper and often better quality than what you'd get now.