I've bought a lot of blades. A lot of duplicate blades too, though I think geko is ahead of me here.
(Less than a few here though, I suspect they are well into the 5 figure mark... speedy/hookshot...)
Two things strike me.
1) Expensive blades aren't more consistent from blade to blade.
2) There is a reason why cheap blades are cheap.
I've seen expensive blades that vary by 10g. I've seen expensive blades that were very light and very hard, very heavy and very soft and everything in between. I've even seen expensive blades with dodgy plies that have a nice gradient - 0.4mm on one side, 0.6mm on the other (Butterfly...). I've seen expensive blades that feel great... and the next one felt terrible.
I've also see all of the above on cheap blades.
One thing I've never had on an expensive blade though, is the neck fall apart from a table impact. I've seen these on numerous cheap blades. I've seen cheap blades have their plies delaminate and separate after a hit (I've seen this one an expensive blade too, but that was more of a design fault than anything). I've even seen cheap blades of the same model with different wood.
My 2nd favourite blade is a cheap $15 blade.
My favourite? Well, that one was $150.