If you're looking for a reasonably priced, high performance butterfly knife, you'll want to consider a McAhron Custom Balisong.
This McAhron butterfly knife has a deep hollow ground Bowie blade that is hand satin finished CPM-154 steel and features a crowned spine with swedge, hardened steel tang pins and short tang ears. Skeletonized handles with blue/black G-10 over gold anodized titanium liners. The pivots have silicon bronze bushings and washers that perform well and keep handle play to a minimum. The handle uses stainless spacers and a black G10 roller style latch.
Specifications:
Overall Length: 9.875"
Blade Length: 4.375"
Cutting Edge: 4"
Blade Thickness: 0.17"
Blade Material: CPM-154
Handle Material: Blue/Black G10 & Titanium Liners
Handle Length: 5.4"
Handle Thickness: 0.52"
Closed Length: 5.875"
Weight: 4.4 oz.