Healthy Nagato would destroy Minato. As much a I like Minato, it's just unreasonable to say he would win. Nagato would win for a few reasons, one being he can use multiple paths at the same time, so in theory he could keep using hungry ghost path and absorb every rasengan Minato throws his way. The only other thing Minato has is his FTG and seals, his FTG could keep him out of danger for only so long, and he would not be able to seal Nagato. As well as this, Nagato has one of, if not the most devastating arsenal of jutsu we have seen to date, Minato would not be able to deal with it.