From a practical point of view, the

From a practical point of view, there is no guarantee that the lower-level decision maker is looking for an optimal reaction to the prices since it is also aware of the combinatorial nature of the problem. It can reasonably be assumed that the lower-level decision maker would be satisfied with a fast to compute suboptimal solution. As a consequence, the use of (meta)heuristics is justified in the sense that a bi-level solution close to bilevel feasibility could be obtained in practices by softening the optimality constraint of the lower-level problem.