The reason implants cost so much is. the imported technology and parts to do them. That's what I've been told.
I was quoted 66,500bht, which included a bone graft (if I needed it) at Edelweiss on Sukhumvit yesterday. That's the cheaper Korean implant and crown they also have a US and Swiss (the most expensive)
I think you'll find that anywhere in the world skilled work will cost. An implant is not the only solution, dentures are far cheaper and probably what most Thais go for