Tbh siacoin is really good project but sadly Dev doesn't plan to maximize the total coin supply cap at an amount (Currently)
Even with the inflation % rate, if the coins supply goes unlimited, i think it will never reach a high price but guess Dev doesn't want the coin to reach high price.
I remember once he said that he wanted offer this service so everyone can use and pay for the storage service for cheap price so yeah
Everyday many sia coins are burned and taken out of supply forever. That's why the inflation is kept in place, it simply replaces the coins that are burned.
From the siatalk forums:
"A key part of Sia's approach to stopping Sybil attackers is proof-of-burn. Hosts burn coins by sending them to a provably unspendable address. Hosts are expected to burn a portion of their revenue (~4%) as a demonstration that they are real. Renters will select hosts that have burned coins with a probability that grows in a linear relationship to the total number of coins burned. Therefore, a host that has burned 2x as many coins will be twice as likely to be selected as another host that has all other factors the same. This provides a very important defence against Sybil attacks. An attacker that is trying to manipulate a renter will need to have all of the excess redundancy of a file before being able to commit an attack. For a file with 3x redundancy, that means the attacker will need to get at least 2.1x of that redundancy, which means that the attacker will need to burn enough coins to look like 67% of the network. That entails burning 1.5x as many coins as the rest of the network has burned combined. Especially as the network grows and matures, collecting that many coins is going to be prohibitive. Unlike proof-of-stake systems, it's not sufficient to just collect those coins, they actually need to be burned, which means there's no chance of recovering that investment. While not wholly infeasible, performing a Sybil attack on Sia should be more expensive than performing a 51% attack on Bitcoin. Even better, paranoid renters can protect themselves more fully by using a higher redundancy. Renters storing at 10x redundancy are safe unless the attacker looks like 91% of the network, requiring the attacker to burn 9x as many coins as the rest of the network combined to be successful."
i bought 90k 
?
