Which country will be affordable and best for my further studies? I'm pursuing BDS right now.?

Considering your BDS qualification, it's actually good to look for an affordable country. Because even if you wanted to target the USA for this, it would not be idle. A BDS degree is as recognized in the USA as one might think. DDS is more common there. 

For your situation, I want to suggest Australia. I can guarantee you that Australia has no such limitations when it comes to BDS degrees. You can easily choose a masters program in dental or healthcare in Australia with your BDS plus the affordability. Compared to the USA, UK, Canada and other major countries, Australia is much cheaper. And scholarships are also more common for Australian universities as they have many tie-ups with India.

One more important thing I want to mention is the right to practice medicine. The healthcare sector has certain limitations when it comes to working in a different country. Your license obtained may not be eligible to other countries and you have to pass an exam. Australian permits are allowed in New Zealand as well. Now I know that you may not want to go to New Zealand for a job. But it's better to have an option, right?

Australia's leading institutes rank very high in world universities ranking. And currently, the healthcare and agriculture industries in Australia are at their best. Basically, you will be picking a good and affordable country in its prime for your chosen subject. I would highly recommend it.

But to do that, you have to know which universities you are eligible to apply to. You can directly get in touch with experts for FREE and get your profile evaluated. They will help you brainstorm and narrow down the best options suitable for your profile and preferences. I'm sure it would ease out a lot of your tasks and help make an informed decision. 

Let me know if this helps and if you want any more information from my end.