IMO, 30 lb is not really that heavy.
My Trek 520 tips the scale at 29 lb.
Without a lot of crazy part shuffling-
get a lighter fork- a steel fork.
Try some Schwalbe Supreme tires- in 50x559 size they are light
and will give you the shock absorbency for commuting.
OR
with the $900 in your projections build up a new bike-
like a CrossCheck.