This study considers transport-price contracts in a two-country duopoly model with firm-specific carriers. It is well-known that when an upstream firm fails to commit to keeping its transaction (or transport) price after a downstream firm's R&D investment, it causes the hold-up problem and diminishes the incentive for R&D investment. While previous literature emphasizes that the commitment to keep the transaction price is needed to overcome the hold-up problem, we show that this commitment may harm all firms. We also discuss the robustness of our results in cases with R&D spillovers, product differentiation, and non-linear production costs.