I made a statement on the fact that Kevin Shirley himself said that a decent budget production is not going to make its money back on record sales. And that interview was published on December 1, 2010 - after The Final Frontier was released.
Tyranny of Souls was primarily done by Bruce Dickinson and Roy Z. Roy Z co-wrote, produced, played all guitars plus bass on a few tracks, and was credited with engineering and mixing the album, along with Stan Katayama. The guitars was probably not done on expensive studio time. And they didn't hire Bob Ludwig to master the album.
Primal Rock Rebellion's Awoken Broken was written and recorded without an external producer, which saves a lot of money, but I don't have the album and can't say who else was involved. Adrian also played bass on the album, and his home studio was likely used for guitars and bass. That is one less man to pay, not to say they don't need to rent a studio that costs a lot of money.
Kevin Shirley is a top name producer and is going to cost a lot of money to hire. It was done in Compass Point Studios in Bahamas, which meant that either they rented their gear there, or they flew in with it - either way, not cheap. The studio itself probably cost a hundred GBP an hour, not counting the cost of the people involved. The Final Frontier was also mastered by Bob Ludwig who is one of the most accomplished in the industry. Aside from those two, they credit several engineers and technician's on the album.
Since they record their playing live, there is going to be a lot of editing done by Kevin Shirley in Pro Tools. That takes a lot of time and he doesn't do it for free.
At the end of the day, the costs are not comparable.