Do you have any idea what Embraer is selling their 190s for? The 717's a bit heavier, but probably a lot more durable in the long run. 30-year old Douglas jets are still flying today. Can't say the same for Embraer jungle jets.
The 100-seater market just doesn't seem to be very big these days. It's probably been killed by regional jets, which can offer higher frequency at lower costs. As far as I know, all U.S. airlines have scrapped their Fokker 100s, and only Northwest still flies DC-9s. Only a handful of smaller airlines, like Airtran, Midwest and Hawaiian bought the 717. And I've never seen a 737-600 or A318 (I think Frontier flies the later). On the other hand, JetBlue did order a bunch of Embraer 190s recently.
Actually, the market for the smaller RJ's is dying and the hot new area is the 100 seat market. Boeing tried twice before to cancel the 717 but was talked out of it by airlines, primarily Airtran I believe. Boeing has abandoned this market segment and the only producer of 100 seat jets is Embrear. Even Canadair doesn't have a jet in this segment yet.
Canadian discount carrier JetsGo started flying F-100s last year- they probably got them from a US carrier. Not sure what the economics of the plane are like, but I had a ride on one and if I didn't know that Fokker was out of business I would've sworn it was brand new.
EMBRAER 145 "Jungle Jet" is in service with all over. They are not well regarded by maintenance staff. Bean Counters love them but I don't know why. I dont like an aircraft with so few exits and such low-time flight crews.
Further, the regional jets are said to be not very economical, then again I don't know the EMB145 sales price currently. RJs take up as much time as jumbos in the air traffic system for less return. They are no friend of mine.