Mustad hooks are half the price of a Gammy or an Owner and neither are twice the hook as a Mustad. I would say the higher end hooks are sharper, a little, but less durable.
Price inflation is due to things that have been mentioned, hooks, lead, and silicone. Don't forget packaging, labels, labor, and all around overhead. The cost to melt the lead (electricity or gas) is much more than it was 20 years ago. Most of your cheaper yet great jigs cut cost by not show casing their product as much and sell them on cards or in just a simple plastic bag.