Maybe I missed something...but I couldn't find if you (OP) were looking for new or used. Anyway...my 2 cents, my thoughts, my opinions...well,maybe 3 cents.
Back in 2000, 2001 looking at DPs or gassers, side by side (new) I found the difference in price (new) side by side was about $30,000. My first (and only) reaction was "I can buy alot of gas for 30 grand". So...I bought a (new) 2001, 33 foot gasser. Ford V-10...at that time the ONLY mfg available. While I realize DPs are smoother and less noise, I got used to the "less than" smoothness real fast, and for the noise...either take my hearing aid out....or turn the radio volume up. Or...just ignore the thing. No biggie either way.
As far as fuel costs go...they probably even out. 7.5 mpg gas vs. 11 mpg diesel. Diesel is around 40-50 cents a gallon more than gas...so........
The only caution: gassers are best way under 40 ft long. Early to mid 30's, IMO is best. Mainly because of the weight. Each slideout is around 1000 pounds plus the frame extensions....in the past some new gassers were so heavy that by the time the driver and passenger get in...you are at or exceed the max weight limit. And...the usual "DPs can go 200,000 miles...." yes. Probably true. But it's only 3000 miles east/west/coast to coast. How many times y'gonna do that?
Bottom line: your bucks, spend them your way...and g'luck!
