Virg,
[Linked Image] A quick price check on a 20kw turned up this:

Onan standby generator
47-GGFE/1858
LP Propane System
MSRP: $17,884.00
YOUR PRICE
$13,995.00
FREE SHIPPING IN THE
CONTINENTAL USA!

Onan standby generator
42-GGFE/1825
Natural Gas System
MSRP: $17,884.00
YOUR PRICE
$13,995.00
FREE SHIPPING IN THE
CONTINENTAL USA!

at least the shipping is free [Linked Image]

Donnie