Yes, there are multiple flights from Thailand to Nagasaki for under ฿ 26,997. The cheapest flight booked recently is on ANA for just ฿ 26,127, but on average you can expect to pay ฿ 31,406.
There are no direct flights from Thailand to Nagasaki, but Cheapflights can provide you with all the information you need to find the fastest route with the fewest stops.
For as low as ฿ 26,127, ANA can have you in Nagasaki from Thailand in 10h 35m.
Currently priced at ฿ 26,127, ANA will fly you from Thailand to Nagasaki and back. In addition to ANA, many other airlines offer competitively priced options for your trip.