Craigslist is hit and miss -- the right person has to come along and see your post.
'Collectibles' is really another term for 'clutter' or 'junk' in my book, so someone like me isn't even remotely interested in what you may be offering, though in a few days the "collector" may come along and want what you have.
I've had amazing success using Craigslist to sell items, but the stuff I've sold are things like furniture, computer, video game system/games, and remodeling items like a bathroom vanity. Oh, I also once sold a ton of landscaping plants & flowers to various people because I was redoing the yard...couldn't believe how many responses I got on the plants! We have also posted a lot of free items and those things will be gone in 30 minutes! People will take anything for free.
From what I've experienced, things that don't seem to sell are collectibles, artwork, adult clothing, and household items like flower vases. People now think Craigslist should be priced like a yard sale I think so that may be why you're not getting any bites. Like I said, the right person has to come along. We tried to sell our old bathroom vanity for over a week with not a single bite, then when I reposted it the following week, we had 4 or 5 people email about it right away.
You would probably have better luck on Ebay for collectible items. Have you thought about whether your prices are too high? My rule on Craigslist is to ask about 50% of the item's cost when it was purchased. If the item is brand new or almost new I usually ask a bit more than that but people aren't going to pay $80 for a $100 item if they can get it from a store for $20 more with a warranty/return policy.