I have created a bandcamp page to be able to display most of the available releases and merch items. You can find songs in full-length for online play as well as free downloads of sold out albums. Purchase of the physical releases is also possible there via paypal. If you want to order something but have no paypal account you can also write an email to boronian.sturmfels(at)gmail.com and pay with bank transfer (but only within the EU).
Have a look at the bandcamp page and feel free to share the downloads and links with other people. The sold out albums will not be re-produced in the same version again, so the downloads are the only chance to get those albums now.