Yea, yea just have to think outside the box when it comes to this stuff, you may find your gear box & shaft for $300, then stumble over a 60 inch deck that has been sitting in someone's garage for 15 years they want to get rid of for $300 complete.
Does make life allot easier to buy a set up, bolt on, and go.
Do try and find a 60, everything is heavier on them, spindles twice normal size, 1 inch shafts, incredible 20 inch blade tip speed. But bring someone strong to load it on the truck, the deck weighs nearly 400 pounds.
Only down side is, it sticks so far out from under the machine, that you don't dare clip a tree with the outside edge. It has so much leverage away from the linkage mounting point, it will bend that in a heart beat.
I cut at half the speed I did with my 48, and still finish the lawn 30% faster than the 48.