I spoke with our Director of Parts today and learned that we can only purchase complete ladders. This wasn't always the case but there's been some consolidation in the last few years with the maker of our ladder and the current owner sells us complete ladders only. Hence the higher cost. Then of course, crating and freighting a ladder is going to be expensive as well.
This all said, for the OP, I'd consider doing some custom fabricating to make repairs.