Depends on the condition. I just sold a Lancea1 and I was offered $1200 but it was almost new condition (only played with for about a week). That was $400 under retail. Take into consideration that most predator dealers sale for 15-20% off retail (some lower if you know someone).
If its mint condition I wouldn't expect more than about $1500 for it. Then I would go down from there depending on use and condition.
Really hard to say.
That being said the SE20 is a pretty cue. I really like the stuff Jacoby makes.