You may also want to check out swap.qth.com and do a search of Omni VI's on there and see what they were going for, also the accursed 'EBa*' can be used as a search, but I usually deduct about 10% - 25% to get a 'realistic' price on what a rig is worth. 

The problem isn't the rig, it's the filters that really cost you. But I have one and it's worth it. (no, it's not for sale either.... Of all my gear that I buy and sell, my Ten Tec gear is NOT for sale)

Good Luck and 73,

Joe