These are the same drives in individual format used in Gecko's bulletproof G540. These DIY kits offer the end user the ability to customize their system for the exact amount of axis requirements they have. They also offer the ability to expand beyond the typical 4 axis limitation, or to build a monster 3D printer. If you require speed, and precision these packages will fit the bill.

These are simply the most cost effective packages of their kind online.

300oz in Stepper Package Gecko G251X Drivers 3 48V 10A Power Supply 3 300oz in Dual Shaft Steppers | eBay

600oz in Stepper Package Gecko G251X Drivers 3 48V 10A Power Supply 3 600oz in Dual Shaft Steppers | eBay