You know i really balked at the price, but will likely still get an army. The logic you're showing really only makes sense in the world of the GW hobby, in relative terms using points as a way to measure value. When you buy an army, you're getting a stack of boxes of different sizes and a load of different kits, likely 2-3x the amount of sprue. With Gargants you're getting 2 different kits in 4 boxes. In absolute, real-world value, it's really poor. It makes sense in the GW world, but in the "buying a product with reasonable profit margin taking into account manufacture, design and distribution costs" it's really poor value. I know that GW haven't actually increased prices above inflation in general as a principle, but this is definitely stretching any value proposal for buying plastic models for a game. Maybe we're too used to to buying 2/3 SC boxes and some other boxes to make an army for £300, but I personally feel the price too much. It should, at most, match a Castellan Knight at £100.
The worst part is the 2 mancrushers at 75. That was £45 literally 3 years ago- £47.50 with inflation. A £30 increase in 3 years is ungenerous considering the age of the kit. They still come with a square base on the sprue!
Having said that, people (including, probably, me) will buy this. So who the hell cares.