Sticky Sitch: Declining My BFF’s Wedding Invite

Very rarely do I miss living in Ohio, but I knew I'd run into this problem eventually.  One of my two BFFs from High School still lives back there and she and her fiance are finally tying the knot! I'm so happy for them, but when I got the wedding invite I realized that it's damn near impossible for me to make it home that weekend.  What's the proper etiquette for turning down a wedding invitation?

It's not that I don't want to be there, but it's during a time of the year where I really can't get out of Boise. I'd be looking at flying out of the Treasure Valley on a Friday after Keke and I get off the air which would put me in Pittsburgh, PA around 10:30 PM and home in Youngstown, OH by 11:45 PM.  The wedding is the next morning about an hour a way from my dad's house where I'd be crashing.  Based on pricing for the flights, the cheapest ($434) flight would put me back in Boise at 9:30 PM on Sunday night and give me about four hours of sleep before getting up for work the next day. I'm weighing the pros and cons of taking that financial/time hit to be there.

Pros: I'd get to celebrate my friend's special day with her and her awesome hubby-to-be and get to party at the reception with my friends from high school that I rarely get a few hours to see when I'm home for Christmas.  If I made it, I'd still feel comfortable inviting them to my hypothetical, future wedding that would most likely be somewhere in the state of Idaho...so she'd end up looking at the same type of pricing for flights as I am.

Cons:  It's $434 for what's really less than 48 hours at home and most of that's gonna be spent in a car commuting from Pittsburgh to Youngstown to Canton and back. Plus, I'd probably need to rent a car or beg my dad to let me use his. I probably wouldn't have the +1 she generously gave me because I know the boy can't swing the time off or travel expenses either.

This is probably one of the toughest friendship decisions I've had to make and the two girls getting married in the office didn't make it easier for me to make.  One of them piped in that she'd never forgive her BFF for skipping her wedding.  What do you guys think I should do? HELP!