Tier 1: 50,000 credit reward - 1,500 repair cost = 48,000 credit gain (Ship prices: 1-220,000 credits)
Tier 2: 70,000 credit reward - 20,000 repair cost = 50,000 credit gain (Ship prices: 620,000-1,260,000 credits)
Tier 3: 85,000 credit reward - 30,000 repair cost = 55,000 credit gain (Ship prices: 2,625,000-3,675,000 credits)
Tier 4: (Ship prices: 6,825,000-9,975,000 credits)
The repair costs for each tier increase so sharply that they consume whatever reward “bonus” the higher tiers get. Which means that unless I buy a premium ship that does not require repairs, I can expect my higher-tier ships to swallow any monetary bonuses I had hoped to gain.
I could literally sit in Tier 1 and grind just as efficiently towards Tier 4 as I could in Tier 3. In fact, since Tier 1 is much simpler and has fewer ace pilots, I stand a better chance of winning and recieving a bigger payment. Which means that at present it is more economical to grind the lower tiers to earn cash.
That’s not much incentive to move up the tiers. Also, take a look at those ship price ranges. If I can expect to earn an average of 50,000 credits per match no matter what tier I’m in, why bother trying to make it to tier 4 when it will literally take me 137 consecutive victories to afford just one of the lowest-grade tier 4 ships? If you consider that most players lose half of their matches, that number goes up to a total of 172 matches. And that’s a conservative estimate that assumes I’m only upgrading from a level 9 tier 3 ship.
With the ship tree rework of 0.8.0 it would take a grand total of 37,640,001 credits, or 753 consecutive victories, or 941 pvp matches to reach the highest level tier 4 ship from tier 1. And that is only if the player focuses on a single ship type, in only one nation, and never upgrades from the mk. I modules that come with the ships. This also assumes the player does not invest in any “dead-end” ship paths.
In conclusion, right now there is no point. There is no reason to grind to a higher tier, except that they get more modules to play with and some slightly different cosmetic designs.