I think it will be buyer collect as PET has a spa connected to a 10 metre long swimming pool.

I have a six person free standing fiber glass spa from GDL it cost 180000 Baht. I find it works well but it holds about 2000 lt of water and has to be changed as there is no good filteration system. Another fault I find is it takes 3-4 hours to reach a good temperature.
I think a concrete in ground spa with a swimming pool type filter would be the best way if for outside. The cost approx 2x2 mt steel & concrete and tiles with a sandwash edge would be around 50k and then spa equip 6 jets and pump about 25k filter and medium 20k plus heater around 20k.
Additions include floor jets light air switches etc which could add I recon another 50k ish.
I have built many swimming pools and some include " complete waste of money" spas!
I do not build for anyone outside my own project but am estimating costs from experience. All my pools use GDL pool equipment - may not be the cheapest but again in my experience very trouble free.