Im more curious than anything else but there are various aftermarket producers of BBC Aluminum Blocks like World, Brodix, Dart, Keith Black, New Century, Donovan

the Price difference is pretty dramatic though... Is the price reflective of quality???
Could you take any of these blocks and still supercharge them without warping?

world is like $4500
DART/ New Century are like $6500
Donovan doesn't list prices so I don't know

Would it be better to look for a machine shop that has used ones for maybe half price?
I have heard good things about Brodix aluminum blocks
I am reluctant to spend my money on anything World bc you hear mixed reviews
thoughts?