It is outrageous.... 50 grand at this stage for any dwelling is extortion especially since planning permission has already been granted... perhaps you should seek out a professional who is not an RIAI architect.... to be honest many of the new members of this havent a bulls notion regarding best practise in construction... and the older members are so stuck in their ways, with their little cliques, that they may not have their clients best interests at heart......
What you need to do is to secure exactly what service you want, rather than have them telling you what they will do for you....
The architect / engineer is not bound by any scale, especially the RIAI....
Perhaps you should be looking further a field, like emplying a Project Manager or Architectural Technician to oversee the build... just check to see if they have the proper PI insurane to certify the work....
to be honest, paying anything more than 4 - 5% is extortion...... ie max 20 - 25 K