Whenever I've sold old PC parts, I've sold CPU/motherboard/RAM as a bundle for about the sum total of typical sold prices for the parts individually, and they've always gone on the first auction and for above the starting bid.
I think you get a fair amount of buyers looking for more than one component and, from such a buyer's point of view, with a bundle they get all the parts together that they know will work, or will only have one point of contact/argument if they don't. They only have to win one auction, pay one lot of P&P (although I usually list that as free in mine and include it in the starting bid) and deal with one seller, so if it's about the same in total as buying them individually then it's more attractive. Second-hand economics are a bit different to new.
From my point of view, I only have to deal with one auction, one buyer, package and post one thing, and I sell all three items. If the bundle ever got no takers then I'd still have the option of selling them individually instead, whereas if I start out selling them individually and one goes, it's less attractive to sell two of those three as a bundle and I might take ages to sell the remainder.
Don't make the AIO part of the bundle: far fewer people will be interested in paying for that.