When it's time to sell.... individual/bulk, auction/dealer

[invictaspur]

What's the best advice.... if you've got a collection with a few standouts in it but a lot of fillers, should you try to offload in bulk or sell off the juicey ones one at a time?

How about the best way of doing it (ie to generate maximum return so I can afford Christmas presents this year?). Approaching dealers or risking it at an auction or ebaying?

One further question, what if someone asks you might what you want for something, and you say, and they offer it to you right away... is it bad form to go 'ohhh, wait, maybe I've undervalued then' ???

Sorry, this is all new to me!