Hi Docking, I'm also considering starting up a Dublin based courier company, Ive been working as a courier for the best part of 7 years and now I'm working managing transport for a warehouse so I could see things from the other side.
To get a footing on the market will be tough with all these big companies under cutting the smaller guys.
Just recently I've heard Pony Express, Hurricane and First Direct have all merged with the intention of dominating the market, they'll provide a c/van for €10(Of which a contractor gets about €5.50)
once picked up and delivered on the same side of the city and €15(€9)
for a transit.
So as you can see its a pretty difficult to make money considering I estimate my break even to be around €2500, (wages,diesel,van,tax,insurance,admin,phone) thats without website sites with customer tracking and any other non essentials.
If picking an a-z route remember that most of these routes are already heavily serviced eg. Dublin to Galway has plenty of carriers, Rocket Transport, Iggy Madden, TNT, DHL, DPD etc.
As for Fastway I heard to start the franchise you need to give €20,000 for your run, use of logo's and ready made customer base, but I dont know if its a yearly fee.
Hope this helps any questions just ask, and best of luck with your venture.