Frankly if you want to save money somewhere, this isn't the place. What's more expensive, another servo, or another plane?
On a plane this big, a U-shaped music is not adequate to join the elevator halves. You won't be pleased with the results. In fact, that's the main reason why you need two elevator servos. A joiner stiff enough to keep one half from twisting away from the other is going to be larger than the space allows.
Must be you're mounting the servos in the tail? If so, just move one servo up and the other servo down so you have straight, mirror-image pushrod runs.
Even better, what kind of radio are you flying? With the right radio, you can plug the second elevator servo into an unused channel, then mix that channel with the elevator channel at -100% for reverse operation. Slick, no muss, and no fuss.