Visitor admission covers activities such as meetings and training discussions, not productive work for the US subsidiary. Repeated short trips to configure customer systems are work, and using visitor entries for them risks refusal at the border and harm to a later petition. The L-1B fees in the USCIS fee schedule are the price of doing it correctly.
A visitor entry cannot substitute for a work classification
Hypothetical example: the company's finance lead proposes flying the engineer down for a week each month to set up grower systems, avoiding the petition fees. The plan fails on its facts. Configuring customers' systems and training the subsidiary's technicians is productive work for the US entity, not the kind of business-visitor activity that admission as a visitor permits.
An officer at the port of entry who learns the purpose of the trip may refuse admission, and a record of refusals or of work performed on visitor entries would then have to be explained in the L-1B petition. The petition costs are set out in the USCIS fee schedule: the I-129 fee, statutory fees that depend on the employer, and the optional premium-processing fee if the company wants a fast decision. Against those known costs, the company should weigh what a refused entry would do to a customer commitment.
The correct comparison is not visitor trips versus L-1B; it is L-1B now versus L-1B later with a damaged record.