I guess it will cost around 200-300$ 2021, what do you guys think?
Since you say we are going to attain that price in 2021 then I think it's something realistic, though we can't say for now because for the fact that the crypto market is now heading towards BNB due to their constant commitment to making the project work doesn't mean that we are going to keep seeing the market heading that way since the crypto market is a free market and very competitive, we might see more project with a very good potential that will shift the attention of investors out of BNB to that project.
For short term, I am very much sure about the prospectus future of BNB coin whereas after few years, it will all depend on the successful run of binance exchange. There are 100s of factors are there to determine the future of binance exchange hence we cannot predict accurate BNB by the year of 2021.