From my catalogues, this could be either an RG570CTTB from the 95 catalogue, or... and RG570GFSVS from 93 but more likely the former.
The CT is believed to be a misprint and should have been GT standing for Gravure Top (basically a photograph of flame maple) These guitars have the AANJ so if the one you're looking at has an AANJ as opposed to an old fender style neck plate, it's more than likely one of these. These guitars also featured a Pau Ferro fingerboard and an Alder body. These guitars had direct mounted pickups with no pickup rings.
The TB stands for Transparent Blue.
The older GF (Gravure Flame) was a more purpley blue and the SVS stands for See through Violet Sunburst. it had a darker bursted edge to the finish and the humbuckers were mounted in rings. The fingerboard was a often a darker rosewood and the headstock did NOT come with the modern tell tale RG series logo under the "swoosh". These guitars had the old bulky neck plate joint at the neck.
I can't but a value on either guitar really as they often are region specific, but I will say that there's a very good condition RG570CTTB for sale near me at £599. However I'm not buying it at that price
Hope that helps somewhat. Oh and I seem to remember our VIP member Kirk had an RG570CT for a while so if he sees this thread he may be able to offer more advice