The Les Paul Copies are always popular. I see them auctioned online at the rate of 20 or more each month, most often selling for $350 to $500. Many times there are a lot of bidders (10-12) too, so these appear to be outselling other Vintage Ibanez guitars. Remember though, large quantities of these were sold back in the 70's too. The 1976 catalog lists 22 different models of Les Paul copies (including two left-handed models). Of course, variations do occur and the flavor of the week on Ebay might be Iceman models. I've seen that happen more than once.
Korina Destroyers often don't reach minimum bid and it's the same for the Korina Rocket Roll models. Unless it's the occasional cheap buy, and those are often equipped with non-stock tuners, pickups and perhaps even the horrid tremelo unit. So deals can be had and if you want a good player this is the way to get it.
Later Destroyers and Rocket Rolls (1980 - 1985) are upping in value of late. $400 - $650 on ebay. Although I saw a nice DT-555 Destroyer (often called the Phil Collen model) get to over $1200 last month. A nice 1976 Ibanez Electric Guitar Catalog was bid to $180 also. Other big price auctions I saw was a 1978 Paul Stanley Iceman bid to $1950 but it still didn't reach reserve. This is a common price region that these early PS10's sell for.
All in all, the best bet for online Vintage Ibanez buying remains auction powerhouse Ebay.com. You will often find what you are seeking immediately and if not, just keep checking every 3 days and within a month you will likely find it. I have also found some at yahoo.com auctions and occasionally on the many classified ad pages out there on the Internet.
For the most recent discussion about collecting vintage Ibanez guitars, basses and late model stuff too, be sure to visit:
Ibanez Collectors World
An informative site run by a John, a great guy and Ibanez fan for years.