Fusion power will be as 'free' as wind power. Both technologies struggle with high installation cost that has to be distributed over the number of customers and the lifetime of the plant. For fission power, the installation is already too high to compete with wind.
but fusion throws out lots of energy. the argument is that the energy will be very very cheap compared to the installation cost (because you just get so much).
Fusion reactors also consume a lot of energy. ITER plans to have a gain factor of 10, making 500MW of heat -- not electricity -- out of 50MW. According to wikipedia, a gain factor of 22 would be needed for commercial operation. The record is a gain factor of 0.67..
If fusion will ever become economically viable is an open question.
Fission also throws out a lot of energy, and the plus side is it's much easier to get to work (which is also the drawback...).
...and that's a good point. After working on fusion for a while, fission certainly looks attractive! I mean, it just works! And for all the hemming and hawing about safety, it's actually remarkably safe (in real terms) compared to just about any other energy source.