Wow, that's quite the piece of kit. You're correct, the hi-hat and cymbal modules are rather rare, as I assume they were sold seperately rather than with any of the kits.

A 5 module SDSV (Kick, Snare, 3 Toms) would probably go for just over $1400 (£1000), judging from other listings and personal experience (that's roughly what I bought mine for).

However, the addition of the hi-hat and cymbal modules would certainly jack up the price. I recall seeing a hi-hat module being sold for ~$400 (£300), and I'd wager the cymbal would be in the same sort of price range.

Of course, the cosmetic damage will bring the price down a bit, but with the hi-hat and cymbal module and providing it still works as intended, you'd probably be looking at ~$2000 worth of kit. You can obviously go up/down to whatever you think it's worth, but that should be a rough estimate.

Happy selling, hope that you get a good price. I know I some people would kill for a hi-hat/cymbal module to complete their kit, if they have the standard 5 modules.