Upgrade path from HF 3 Express + expansion packs to HF 4 Pro?
Hopefully this isn't a FAQ. Googling left me empty handed at least.
Suppose I want to expand my horizons with one or two expansion packs with HF 3 Express, but later discover I really ought to have gone with HF 4 Pro. Is the money spent on the expansion packs entirely lost at that point, or is there an discounted upgrade path for this situation?