Just as Xang says you actually need to compare like with like glass. Look at the prices of the new Canon and Nikon glass for their mirrorless systems for instance, there is a premium over their other older formats. Going back to the A mount days Sony have pretty much always been at the premium end for glass. At SRP the A mount F2.8 trinity were a little more expensive than the Canon or Nikon equivalents, and a lot more than the Tamron versions. The one exception to this premium pricing was the first 18 months of the full frame A7 series when here in Australia had the best pricing in the world as Sony had lots of offers to encourage adoption and local Sony prices were comparatively cheaper than any where else in the world thanks to a stronger Aussie dollar. Then when the dollar started to fall there was a 10-20% price increase and we've been stuck there ever since. Meanwhile increased maturity and adoption of the A7 series has meant that Sony have eased off on the deals available for their premium gear - most sales and cash backs exclude the GM lenses and often some or all of the G series. Despite this many of those lenses are in short supply or back-ordered, indicating strong demand despite the price. Changing camera systems, even for professionals, is no simple exercise. You need to educate yourself and then put into practice. My brother converted from a true-Canon cultist (multiple generations of 5D bodies and 1D) to Sony but only after kidnapping/borrowing my A7Rii for more than 2 weeks, complaining frequently for the first week, asking lots of questions, grumbling about how his adapted Canon lenses were not working properly (MBIV). He flies a commercial 8 bladed drone and none of his control systems initially worked properly with the Sony and he needed new accessories and lots of experimentation before he was happy. Switching him to native glass has resolved many of the remaining niggling issues and he especially loves his 2470GM and the 12-24F4G. He still complains about the menu's and battery life! But what eventually worked for him may not work for others, especially if you are a professional and need to earn a living from this. I am just an amateur happy snapper that has been shooting Sony since I came back to interchangeable lens cameras with an A55 so this has been an evolving journey for me. A55 -> A77 -> A99 +> A77ii +> A7s -> A7rii -> A7Riii. I certainly never expected to end up on full frame with all this quality but expensive glass!