Don't forget the biggest money sink is not the hull but the components with in your ship that will wear out over time and start to fail at a higher probability as they wear. While it is possible to fix the component when it breaks the wear will increase the likelihood it will continue to break until its replaced. The other aspect is better grade components will cost more
Here we can see some of the idea for components
https://robertsspaceindustries.com/electronic-access/components
Here is the tech doc on their idea for components, item grades and item classifications
https://robertsspaceindustries.com/comm-link/engineering/16193-The-Shipyard-Other-Ship-Items
So while most hulls come with the base component of civilian and will require lots of UEC to upgrade to something like military Grade A. (it is still unknown if you will be able to insure the components) they will be huge money sinks. So flying around in your ship will wear out the components which will require replacing by purchase or finding from salvage.
Other money sinks will be land claims, NPC hires, Hangars.
So to answer the OP yes as time goes on the game will experience player wealth creep and players will own more and more ships but hopefully the component costs will keep those ships in their hangars as they would be to costly to just fly around and ganking.
Here we can see some of the idea for components
https://robertsspaceindustries.com/electronic-access/components
Here is the tech doc on their idea for components, item grades and item classifications
https://robertsspaceindustries.com/comm-link/engineering/16193-The-Shipyard-Other-Ship-Items
So while most hulls come with the base component of civilian and will require lots of UEC to upgrade to something like military Grade A. (it is still unknown if you will be able to insure the components) they will be huge money sinks. So flying around in your ship will wear out the components which will require replacing by purchase or finding from salvage.
Other money sinks will be land claims, NPC hires, Hangars.
So to answer the OP yes as time goes on the game will experience player wealth creep and players will own more and more ships but hopefully the component costs will keep those ships in their hangars as they would be to costly to just fly around and ganking.