My BMS with Bluetooth was only $30 delivered by slow-boat from China.
My entire 7 module G2 Leaf pack including charger was under $800.
I like the Zeva BMS, specially for a EV conversion, but for a Golf Cart application that just needs cell protection there are a lot of other effective options.
if the Chevy Volt pack has the BMS tap harness installed, you can tap the existing connector for installing a BMS, the photo below shows the B- and each cell tap available on that connector:
