twenty years ago, the general rule for cost on an Inverter/Charger was $1 per watt. So, if you needed a 3000 watt inverter/charger it was about $3000. But starting about 15 years ago, with do many Motorhomes using Inverter/Chargers, the cost has come way down. The current replacement is the Xantrex freedom 458 2500 watt which is about $1300. You NEED an Inverter/CHARGER! Your system is set up for the Inverter/Charger. The bad news is, you will probably have to also pay for a new Remote panel. Your older remote panel is probably not compatible for the newer Freedom Inverters. You could just work around the Inverter/Charger and put in a standard RV POWER CONVERTER, at least a 70 amp or higher. You will have to remove the 120 input and output romex wires and just connect them together to power the circuits that run thru the Inverter. A good RV POWER CONVERTER 70 amp runs about $300. But, it is best to fix it correctly. Doug