I imagine it could be cheaper actually. You don't need the demand load infrastructure, just the single open structure with one swap mechanism. Shouldn't require personnel, just a bank of batteries that auto load/store/charge. The typical supercharger station costs around $250k.If you think rolling out a fast-charging network is capital intensive, imagine rolling out "plentiful" battery swap stations!
If you read the link, NIO has already proven it's feasible.