From their facebook page- this news:
Brill’s MyBook program, available on the BrillOnline Books and Journals platform, enables users to purchase a print-on-demand paperback copy of books of their choosing, provided they have access to the e-book version via their institution.
MyBook has a fixed price of €25.00 / $25.00* per copy, and is printed in black and white. Brill will ship your copy free of charge, though VAT will be added where applicable.
The Brill MyBook Program is exclusively available on BrillOnline Books and Journals. Look for the MyBook purchase option next to titles of your choice.
That really is quite fantastic.