Something like haubergeon, when scaled down to 45, ought to give at least DEX+2 (in correspondence with Brigandine). Basically, I feel that level 60 gear with +5 stats ought to give +3 stats at level 30 if there's a level 30 piece (same slot) that gives +3 stats. Just an example. I don't feel like scrounging through equipment lists to find comparisons and/or appropriate scaling for gear stats.

(Edited because Haubergeon doesn't give VIT+.... I think)