Hot Toys has a 'formula'. It is profitable within that formula. I wouldn't expect HT to change much given its wide reach and dominance.
InArt doesn't have a proven formula yet at this scale so they are more inclined to do what's necessary in the beginning to drive business and make extra concessions to consumers. Eventually, they will settle in as all companies do. But right now, this is the best time for innovation and extra attention to details... that is, if they can provide what has already been promised.
Remember in HT's early days, due to customer wishes, they actually included a full Ripley figure with their Power Loader at no additional cost? Yes... HT.