Hello Victor and welcome from VA. I have a 2014 R3T with 28K miles on it now. The '14 has ABS which work great at 85 MPH as tested by yours truely to avoid spinning cages on the freeway. Of the two new bikes, I would surely say go with the '14 over the '13 for that reason alone, and it is a year newer thus has slightly more value.
Of the 2 used bkes, I would probably go for the one under warrenty still. The mileage difference is not much by the way I ride and with the warrenty still in affect, I'd go that way.
Now, head over to the introduce yourself section and tell us about your riding life. Again, welcome.