For a beginner / intermediate skate skier,...
For a beginner / intermediate skate skier, is there a worthy diffence to spend the extra money for LF waxes versus CH waxes?
No. I would stick with the cheap stuff and focus on waxing it at least every other time out. The difference between the two has been debated to begin with. Given your interest in skate skiing, get yourself a good bronze brush and nylon brush and focus on brushing you skis throughly. You'll notice a bigger difference doing this than you will using an LF wax.
I agree - brushing is really important. The colder the temps the more the wax will get squeezed out of the base and slow down the ski. Also try using a spray bottle (with water) before using the bronze brush, the loose wax will come off quicker.