Yes, typically it looks like you need to buy a command group and 3 sets of infantry to make up an infantry unit. Overall around £19 per unit.
For cavalry you need only 2 sets, both of which often seem to contain command figures, which is odd. 12 figures would also be around £19. Plus postage for both, whatever that might be from Switzerland. So not exactly cheap but there are some figures that aren't readily available elsewhere so you get what you pay for I guess.
The artillery is single pieces, (£3.50-£4.50 or so), so you can buy one or two as needed, which is helpful.
Perhaps most tempting are the goblin spider riders, no one else does those that I'm aware of, £4.50-ish for 6.
The dark elf range looks tasty as well.