The filing charge and optional premium processing from the USCIS fee schedule, plus significant internal and professional time assembling technical, transactional and payroll evidence.
The acquisition makes the evidence work larger, not smaller
Government charges are published and predictable. The variable cost is the evidence, and an acquisition roughly doubles it because two organisations' records must be assembled and connected. Someone has to retrieve the purchase agreement and its schedules, confirm which intellectual property actually transferred, locate development records that may sit in the acquired company's old systems, obtain payroll from a predecessor's provider, and write the replacement-training analysis.
For a small manufacturer this is meaningful time from senior technical staff. Requests for further evidence are common in L-1B generally and more likely where the knowledge originated elsewhere, so budget for a second round of professional work. Premium processing accelerates the decision but not the preparation, and buying speed before the acquisition chain is documented simply brings forward the moment the gap is identified.