Should We Go To Bangkok?

We are thinking to make a plan for next month holiday. We are not sure where we want to go during the holiday season. For sure, we want to bring our kids to a nice place. They are busy for most of the time with their school and I think they deserve to get special holiday during their end of the year's holiday.

My brother in law probably will fly to Bangkok from Europe. He have some meetings in that place. And he also have a friend there that we want to see. Since we are not really far from Bangkok at this time, should we also fly to Bangkok? Will it be an expensive holiday for us ? I still have no idea. I did not make any bookings or plans yet regarding holiday plan. I have to collect some information first before we can finally decide if we will fly to Bangkok or not. So far, I did not see that there is an interesting place to visit for the children there. It will be easier if we go to Hongkong since we can bring our kids to Hongkong Disney.