Renewables are massively cheaper than anything else on the market today, and this is one of the reasons I am definitely in favor of them. One thing to consider though is that the capacity factor (basically how much of GWh you actually produce from your available capacity) of renewables is less than coal/nuclear plants, so in that case 1GW of solar and 1GW of nuclear is not the same. But even with this taken into account, renewables are the cheapest and there is virtually no chance for this to change in the future.
I'd imagine there's a certain size above where nuclear becomes cheaper even with the added costs of mining for fuel, waste management, etc. (Eg. the manufacturing, setup, maintenance, decommissioning of millions of solar panels and wind turbines, distribution network to connect them will be offset by a few very large nuclear plants. Especially if they are fuel efficient [eg. fast reactors].)
