is it a custom CQC7, a EKI '7, waved or not waved, or a BM 970 CQC7? tanto or spearpoint too makes a little diff,
a specwar '7 is about $1200 or so probably a little higher.
a std EKI '7 is ~ $100 or so unwaved, a little more if waved. maybe add $10 if its a spearpoint.
a BM 970/975/etc '7 is also ~$100 or so, for the std models (the ti blade ones are kinda pricey now but pretty rare)
of course thats in LNIB shape, and is low end, put one on ebay/etc ya could get more, not a lot more though, $25 to $50 i would say, tops.
as far as testing them, its an older design and has withstood the test of time, a great design imho, that said i prefer a SOCFK myself, or a CQC6 if ya are talking custom.