There seems to be quite some confusion in this thread about three concepts that do not necessarily mean the same:
- "no frills airline"
- "low fares airline"
- "low cost airline"
You can be a low cost airline with high fares and no frills, but also a no frills airline with low fares and high costs. Or whatever combination you can make up (although some combinations will make for a quick exit from the market for sure).