Originally Posted by
brain fade
The Embraer IS what you hint at. A jet aircraft with turboprop costs- which is why they have sold over 1000 of them!
The main reason the Embraer can cost (very broadly) the same as the Q400 is because it is half the size, especially the Emb-135. So while your costs can be comparable you cannot get the same revenue.
Start speaking seat-mile costs and things change. Of course, if the seats are unsold because you are operating at 40% load factors things change again. So I prefer actual passenger-mile costs.
Incidentally the Emb-135/145 is now effectively out of production, just like the basic 50-seat Canadair RJ has been stopped as well, only a few business jet variants continue to be produced. Embraer have moved on to bigger things and there is an increasing pile of stored 50-seat RJs building up (including quite a number never delivered), generally more Canadairs than Embraers - which may well interest SAS.