The higher level gear itself is quite expensive
Players earn PvP experience points and Wolf Marks for participating in PvP. Each winning match nets 50-60 marks and 30-40 experience points while each losing match only brings in around 10 marks and 10 PvP experience points. Marks can be used at the various NPCs at the Wolves’ Den while PvP experience points increase your PvP level. As you increase your PvP level, you can unlock PvP specific abilities.
There are currently three tiers of rewards: item level 55 gear (crafted), item level 70 gear, and item level 90 gear. Naturally, the item level 90 gear is very good, but it requires a PvP rank of level 30 to use. It took me around 50 matches to hit level 8; buy ff14 gil I expect it will take around 500 to get to rank 30 given that the amount of experience points required to level up increases with each level.
The higher level gear itself is quite expensive too. After about 50 matches, I was able to accrue enough Wolf Marks to buy a single item level 70 piece (without many marks left over). The item level 90 gear is about 4 times the price of item level 70 gear – it will literally require over 1000 matches to get a full set of item level 90 gear.