I'd agree 25/50 seems a bit steep for T1000, but its certainly workable, just don't have them doubling every 15mins. We have the same level 25/50 L1 blinds but buy in for T2500. We based our structure on the Tex's Tears site - http://www.texstears.com/ - Tex Morgan's Tournament Evaluation And Rating System - great software for anyone who runs or evaluates poker tournaments. A good structure for you retaining your 25/50 start might be the one here http://texstears.com/FNRE1.html