I don't understand why you think that converting the front to a 48/34 or even a 48/32 would be such an expensive option. It looks to me like it would only involve replacing the two front chainrings. Depending on how your chain was sized originally you MIGHT need a little longer chain. that would give you both an easier hill climb gear and a little faster flat road gear.

What's your favorite flat road gear with no wind? If I could duplicate that with a 48/15 to 48/19, that's what I would definitely do.