How many hours are you getting off of a single string bed? Do you use Wilson CC on both your rackets?
Replacing your gut with pacific classic will cut down the cost of your string bed. I can't say you'll like the feel of it as that's something you'll have to feel for yourself. My cost for my string bed on the sig is less than $40, being split between two rackets. That's a reasonable cost for me and I'm sure I can get over 12 hours from this. I'm praying for 20 though.