Surprisingly not really. The cost of fissile material is extremely small relative to the cost of generated electricity. Raw uranium contributes $0.0015/kWh to the cost of nuclear power. In breeders it’s $0.000015/kWh. The article I linked suggested that even today sweater extraction costs just double what mining costs, so 3/10th of a cent per kWh.
This is why we don’t use breeder reactors right now. The cost of uranium is a rounding error relative to the value of the generated electricity.
"Suggested cost" is speculative. We won't know what it will really cost to scale until we actually start doing it.
There are also reasons to use breeders beyond fuel cost, such as dramatically decreasing the amount of waste and the time the waste is hazardous; both are reduced by 100x each IIRC.
Yes, but that's not so easily mined. Point being that the cost of nuclear power will go up once the easily mined material is consumed.