The playline ones can be found on Ali Express, etc. Their clothing is playline level, maybe a smidge better than some Barbie dolls.

The collector Defa Lucy dolls are sold on the Defa Lucy website: https://defalucy.com/

I highly recommend following their Instagram account as they do post when a doll will be a released, usually just a couple days before they do it. The dolls are very limited and most sell out in minutes.

I also recommend joining a Facebook group, which I think is called Defa Lucy VIP Club or something like that. It's run by Rudi of RND Collectibles. He sometimes gets an ultra limited edition exclusive. The only way to know about those are to be in the group and kind of be in the right place at the right time.

I only have one of each. Here's a photo of a collector version, Series 1 Model 1.5, and a playline one from the denim line.

.