Why are cold water belt drive pressure washers priced so differently for machines with similar specs. I see 5.5 gpm machines from $1,800 to $3,500. They all have similar specs and name brand pumps (CAT, General, Comet, Giant) Does it just come down to a higher end model for the same pump? I would like to upgrade from my 4gpm 3500 PSI belt drive (Giant P316 pump, Honda engine) to a 5.5 gpm machine. I would like some advice and opinions .