IT, NGT, NTT, CT, ST are in the same Tiger family but totally different fish from different reigns of the world, for example correct me if Im wrong. IT is from Indo, ST is from Mekong Rivers of Thailand and CT are from Cambodia and Vietnams Mekong Rivers. Being that ST are such nice fishes, its been fished to extinction and can only be purchase from private collectors. Until now, Datnoids are still unable to breed in captivity so an almost extinct fish will fitch high $$$. CT however are still in the market overseas but expect to pay high $$$ as well, They barely got introduce to the US market not too long ago so it still fitch pretty high amount bc its still pretty rare are hard to find. I still remember way back about 10 yrs ago ST were selling for $20 each..... but since they banned it from import few years ago and Thailand declared them endanger the price sky rocket..... I love all Datnoids, however I love CT and ST the most and I'll tell you why. ITs are pretty much 90% unstable, they might be stable in ur tank, but once its stress it just turns dark. NGTs are super territorial, can only have 1 or they will fight to the death or until someone runs. NTT always hides, if u have a big tank, you will only see it when its feeding time. CTs and STs are by far the best tank mates, they just curse ur tank all the time, 100% stable even when taken out of the water. All these info can be research on the internet but nothing will educate you more then having one urself.... I hope that helps.......
Cheers
Cam