Touring plan

I would like to let you know that your travel period falls on the long national holiday in VN. This means all services are super expensive on those days. May I recommend moving your plan to another week/day to avoid the peak season as well as the crowds?

Good work. I understood everything perfectly. 'Super' is an informal word; it doesnt sound very professional. I kept the second sentence simple because you mention it is 'peak season' and that there are 'crowds' of people at the end of the paragraph.