Any schoolbus replaced pursuant to this part that meets the federal safety standards established in 1977 shall be offered for sale to school districts to replace schoolbuses that do not meet the federal safety standards, at a purchase price not to exceed the amount of the school district or county office of education’s contribution specified in Section 17921, plus appropriate administrative costs. This section shall not apply if the school district or county office of education certifies a continued need for the schoolbus being replaced.