Yes the cost of depositing nuclear waste is trivial, it takes a small number of large concrete structures underground in well picked locations.

The US produces about 1250 cubic meters of waste per year. For comparison the empire state building has a floor area of 208000 square meters, assuming a 3 meter floor height you could fit about 500 years worth of spent fuel inside it.

Yes. This. Nuclear waste storage is extremely cheap.

Also, we only "use" 3% of the fuel in current nuclear power station designs so we could just reprocess the fuel and vastly reduce the volume of waste too.