So sad we could not apply economy of scale for nuclear... The main reason solar and batteries are so cheap is economy of scale.
France plans to build a series of six reactors for its EPR2 programme with each reactor scheduled for completion 1-2 years apart, but that is only expected to reduce costs by 30% compared to the (hugely expensive) EPR.
Small modular reactors hope to improve things but it's far from clear they will end up any cheaper. Historically making reactors bigger makes them more efficient. The Rolls Royce SMR is just under 1/3rd of the size of the EPR so even if successful any cost reductions are not likely to be dramatic.
This isnt for a lack of investment either.
Gas is also waaaay cheaper than equivalent amounts of nuclear power - like 3x cheaper.