No. Both are filed on Form I-129 with the same base fee, anti-fraud fee and any applicable asylum-program fee, and premium processing is optional for either. The difference in cost lies in the evidence, because an L-1B file needs technical documentation that an L-1A file does not.
Same filing fees, a different evidence bill
The USCIS fee schedule on Form G-1055 sets one set of charges for the L classification regardless of whether the beneficiary is a manager or a specialized-knowledge employee: the Form I-129 base fee, the fraud-prevention and detection fee and, unless the petitioner is exempt or a small employer, the asylum-program fee. Premium processing can be added to either for a faster decision. Where an L-1B costs more is in preparation.
The greenhouse will need its protocol written up in a form that an adjudicator with no horticultural background can follow, technical exhibits organized and explained, certified translations of French-language manuals and reports, and possibly a short expert statement from within the company describing how long the knowledge takes to acquire. Those hours are the real price of the category. Family members apply for L-2 status separately at the port of entry as Canadians, and any later extension of the assignment carries a new petition fee.
Budget for the possibility of a request for evidence without assuming one will issue.