You can get a shunt here for $27, wire for $1.35/ft, and the meter for $152.
Worth every penny.
If you don't believe me just wait until you have your first low battery issue, and your trying to figure out what is happening.
It is not if
your going to have a battery problem, it is when
Trimetric TM-2025-RV Battery Monitor System
06 Hurricane 34FT WH W20 Chassis 8.1L 120K, Steersafe, Koni Shocks, DIY Trac Bar, Tri-Metric 2025RV Battery Monitor, 4-6V Batteries, Scan Gauge 2, Crossfires, 735W Solar Morningstar MPPT-60, KVH R5 In-Motion Sat, XM Radio, 07 Chevy Malibu Maxx Toad, Falcon 2, Brake Buddy, Escapee