Hot Toys' prices aren't going UP when they introduce these new bodies. They're staying the same. Their prices are based on how many figures they sell, which is substantially less than Sideshow. Their development cost on a figure likely isn't any less than Sideshow(probably higher, considering the difference in quality of accessories), but they have to spread that cost across fewer figures. Which equals higher prices. But they're still not going up.
Costing this out is similar to what I tried to argue when people were talking about how much a 1/6 scale Yoda should cost. Many toy companies, most smaller than Sideshow, can afford to design, sculpt, and tool a figure with 30+ points of articulation, at a $15 pricepoint, while selling less than 10,000 pieces of that figure(actually SOTA, the company that explained all this, has a breakeven point of 7500 figures or so, but they're a very small company, so I'm bumping it up). That 10,000 breakeven number drops when the company is getting the full retail price instead of wholesale to retailers.
Now, those are not 12" figures. More like 6". But the cost differences in tooling a 30+ points of articulation body with high detail at six inch does not sound necessarily easier or cheaper to do than a very simple generic body with 30+POA at 12". Steel tooling is steel tooling, and undetailed tubes don't sound like they'd be difficult to do, relatively.
Sideshow produces how many 12" figures a year? A couple hundred thousand, if you look at all the runs of all the figures in all the lines. Some have minor differences, but by and large they're the same bodies. They can amortize the cost of an upgrade over the hundreds of thousands of figures they produce every year. If they add $5 a figure to pay for such an increase, then that's over a million dollars. Which would be a ridiculous amount of money to spend on designing, sculpting, and tooling a new body. Especially since they wouldn't have to update it every year, so every year the cost of the new body decreases to next to nothing. Even in year one it'd likely be under a dollar per figure(and remember these are all $50+ now).
Sideshow can do it, they can afford to do it without raising prices, we want them to do it, now we just need to see if they are WILLING to do it.