Thank you for the question.
It's pretty hard to say at this point, because the costing has to be done over time. If these technologies were to become very effective in the future, then perhaps we would find that the amounts currently invested were not so high after all. However, we can't know. Governments haven't always been in the best position to determine the best technologies to develop for the future.
What's interesting about an explicit carbon price is that there is already an incentive to develop technologies through pricing. That's not always enough, but I think pricing should be the main channel to encourage technology development, rather than the subsidy, because it's pretty hard for the government to know which solution is better to subsidize.