Well, uh... I own a Billy Goat...
These are the list prices I've got including trailers
The Fradan 31hp is $6,579
The Fradan 35hp is $9,899
The Billy Goat 35hp is $7,224
The Monster 35hp is $10,999
Watch the weight on these units. Hauling around almost twice the weight of the Billy Goat will add up with fuel consumption.
The 31 Fradan is not in the same class as the 35. If you're serious about the Fradan 31 look at the Billy Goat 25. Performance wise I'd put the 25 up against that 31 all day long. In dry leaves the 14" hose Fradan will consume higher volume than the Billy Goat because of the hose, but in wet/moist conditions the 12" hose Billy Goat superior lift will run circles around the competition. Don't take my word, get a demo before you drop your hard earned cash.