There's 2 ways to look at a big boy loke an 880. One way is "why dump all that money?" You could nurse a 660 through the task and not be out 2k.
The other is "once it's paid for, its there to have in the future". its like the rest of the tools we own. It was an expense to acquire them, but once we got them, they wee there to earn their keep going forward.
I myself would not go buy an 880. Here in my neck of the woods there is NO use for one. A 90 some cc saw with a 36" bar is plenty here, usually. But, I dont live in the land of the monarchs either. If you buy that combo, how often will it make its way to the job? I feel that if it isnt out twice a month, than it isnt necessary.