The deflationary coins are created with a very straight forward concept. You buy them and hold them till the time there supply goes down and when there demand goes beyond there existing circulation then you can claim your profit. If you have courage to wait then you can go for it.
I keep on saying but no one is listening that you don't just need to buy and HODL these deflationary coins. Even if there supply go down to minimum the price will go up only if they have some utility like solving the real world problem. Don't think that burning the coin alone will increase the price.