An advantage in
buying a system from a mfg and not a home built system is that that manufactured one is tested and guaranteed. When you assemble
parts into a system no part supplier will take responsibility for the system fail... nor possibly understand what happened and why. Some times you save
money and buy lots of problems... if not in the near term... then down the road.
Boat stuff is often overpriced... this is a well known fact. But why? They can get away with it!