i haven't FBA in 2 years now. FBM is very lucrative, i have access to the premier online marketplace buyers, maintain control of all my inventory, i list hundreds of sku at a time without any storage fees, every order goes out within 24 hours, the money shows up in my account the instant the shipping label prints and i can disburse the money to bank every day if i want to.
with FBM, i have none of the non-compensated extra work and time spent trying to figure out where amazon screwed up with my inventory and trying to claw back some compensation for their mistake. every item i sell is packaged perfectly every time - 0 returns for item being damaged. with new amazon shipping discounts , a dollar or 2 more to send UPS ground across the country compared to the next state, my margins have never been better .