Courtney Love's biographer -- one of the best in the biz -- says he went through hell to write her life story ... and claims his reward was getting canned without notice, and then shortchanged on his paycheck.
Anthony Bozza is suing Love, claiming he got paid $100,000 for his work ... but their deal calls for him to get paid an additional $200k.
Bozza -- who has written with the likes of Slash, Tommy Lee, Tracy Morgan and Artie Lange -- claims he incurred $10,000 in expenses ... and didn't receive a dime in reimbursement. He also claims Love would disappear for months at a time, which caused him to deliver the manuscript late.
In the end, Bozza claims he was never officially fired, but says Love texted him that she was "fixing" the book, and she'd already hired a new writer to rework his version.
Bozza is suing for breach of contract and wants the $200k he claims he's owed, plus interest.