Read on the TAMB previously that the away allocation for the Euro qualifiers has dropped from 10% to 5% of ground capacity . WC qualifiers remain at 10% ground capacity Cant find anything on Uefa website about it

If true away tickets likely to be in shorter supply for teams with good away support, but an additional 2500 tickets available for home BB's in a Euro campaign. (although even in a WC campagin the FAI could likely sell another 2-3000 tickets as the vast majortiy of away teams are unlikely to take up their full allocation of 5000).