I've taken one apart for shipping and then mine for storage. I found both times that some pieces will come apart and some absolutely will not. I had to pull pretty hard to get anything to budge but if it didn't look like it was going to, I just stopped so it wouldn't break.
I've wondered if applying heat with a hair dryer would soften the plastic enough to get it apart. It would be SO much easier to store if the roof would come off!
The one I shipped, I had about half of it dismantled and half together. It required a big box but it worked out okay. I sent it via fedex for $36 domestic about a year ago but I see you are not in the US! I thought the shipping was pretty reasonable here in the States but don't know about yours!