I have the base game and really enjoy it, enough so that I plan to buy all of the expansions for the game.
I went looking online to get Something Wicked and it appears to be sold out everywhere including Flying Frog's website at the moment. I emailed FFP and got the response that they will be reprinting the Something Wicked expansion but they haven't nailed down the exact date as of yet.
The Coast expansion however is still available at a number of places. Can the Coast be played without Something Wicked? Is there any reason I should buy one before the other?
Absolutely it can be played without Something Wicked. The only difference will be difficulty - The Coast is harder than Something Wicked. But that shouldn't be a problem for a courageous investigator...