There's nothing to really understand. Companies will increase the price because they either A) They just feel like it or B) They have reasons behind that scenes that we'll never fully know. Licensing, greed, mandate from the license giver, actors asking for a higher price, etc. When has an increase in price in this hobby ever really been "justified"? Did Hot Toys slapping 5% of diecast in their Iron Man figure justify the increase of $200? No but they did so anyway and now Iron Man figures are $400-$450 for a little bit of metal. They're thankfully better proportioned now but that just came with time, not them asking for more money.
We're seeing the same thing with their Hono figures. Started off at $160 and they're now already at the $215 price point. Only took them 8 months and they started off the line saying they'll be "entry graded' priced. This isn't the first nor the last we'll see a price increase. They don't care. None of these companies do.
These figures costing more doesn't mean you're getting a better figure either. That's the sad reality and always has been. Hot Toys/INART/JND isn't thinking
"Oh we're charging $50 more for this figure, it should be $50 more accurate and higher in quality".