I have zero qualms about paying $29.99 for a 6 inch Grievous. There needs to be a ton of articulation, potentially two sets of arms, 4 lightsabers, a blaster, and there SHOULD be a cape included, but I can see Hasbro skipping that. I can see how all of that would add up in terms of expenses.
But $29.99 for the regular line? Absolutely not, unless there are multiple heads/hands included along with multiple accessories. Make them like Hasbro's version of MAFEX/SH Figuarts figures.