Also if you tot up blood of the phoenix then it's 32% off RRP so it may be warming the shelves but compared with buying separately it is reasonable.
This is of course all before any store discounts as well.
Does it have as much in as calth? Clearly not. However calth was also released a few years back and prices have risen since then. Calth was also an entry point to heresy. Comparing it to dark imperium is appropriate, this isn't a core set so not priced as such.
I remember when Battleforces were £40 and my first set of 40k was £34.99. Inflation counts for a lot.
As such, my previous point stands. If you're paying full retail for the models in the box not including characters it'd set you back £90.50
Buying this you're either seeing it as cheap characters or cheap units. Based on the above, £15 for ghazghkull, Makari and Ragnar IS a bargain. Just depends whether you need nobs and incursors.
Bargain. That means you're paying £15 for ghaz Mak and Ragnar. Wowsers
Bargain? How? 
It should be 110-125$ tops. Calth box costed 1/4 less, had twice the amount of minis, all new ones at that, plus a whole free nice boardgame. It's sad people already forgot SC and battle boxes really used to be a bargain, not a paltry few % off and that's only thanks to a few less desirable units thrown in. Similarly "bargain" Phoenix box still warms the shelves...
Calth also was £95 so NOT a quarter less at all, it's about 10% less than this box...