As far as SCN-SEN is concerned, having a basic entry fare of 49 euros available for all dates is probably as good a way as any of gauging demand. Profit/loss for the first few months is less important than ensuring that you get a transfer of pax onto the route from those who currently use other departure points to London. It should also help identify the strength or otherwise of the potential for leisure traffic and the weighting for each day of operation with a view to schedule adjustments as appropriate.
With DRS-LON being only a recently vacated route it might have been expected that there would be more variable fares from day one. I'm not aware of what the fare levels were when bmi/LH operated DRS-LHR until March this year.
One would expect Panta to have budgeted for losing a reasonable amount of money on their new OLT routes with the initial aim being to establish a good client base. I would assume they have the resources as well as "a good grip on revenue management" in view of their previous industry experience.