I have an idea for you.
The hardest part of selling a complete army is that any given person's collection will never be exactly what someone else is looking to play. The further away you get from the actual "wanted" state of an army, the less likely a trade becomes, which is why most armies tend to sit around until the owner caves in to selling it piecemeal. Ponder this for a moment.
I've recently started playing Necrons. I traded out my Tau for Necrons, and got a lot of things I didn't want: Extra warriors, 8 flayed ones, 10 destroyers....and I didn't get enough of what I did want: a third monolith, enough wraiths, a deceiver, tomb spyders....I've since been trading across Dakka and Bartertown to fill in the missing pieces. I just got 2x wraiths and 5 immortals in the mail for one trade, traded out 4x destroyers and a Lord with a Rez Orb for a monolith and two wraiths....and have a couple other trades in the works that will hopefully net me three more tomb spyders and a couple more wraiths (I have five wraiths right now).
Tomb spyders on the other hand, I'm not having so much luck with. Stores don't carry them because 1. They're direct order only, and 2. No one uses them. thewarstore.com doesn't carry them, and my trade efforts have mostly been met with blank stares; not very many people have Tomb Spyders, and I'm told that they never picked up in popularity in 4th edition because of their point cost and utility (or lack of).
Nonetheless....I find myself trying to create a list centered around 9x Tomb Spyders that each spit out a T6 scarab, with 30 more scarabs on the field causing a mess of things.
The morale of the whole story is that I'd like to buy your tomb spyders (and your scarabs) for my own eccentric use. While you may currently be loathe to break apart any pieces of your army for sale....I assure you that selling them to be separately will probably increase the attractiveness of your army to potential buyers - Necron players play destroyer heavy, dual monolith lists with variations of things, but the one thing that holds fast is that scarabs are unpopular, and tomb spyders are literally non-existent in any Necron player's list.
Please let me know.
PS: I'd like your Deceiver too! I'd go into long explanation here as well to add convincing, but suffice to say that most Necron players believe C'Tans to be wasted points. =p