Just for your information no one pays $4000 for a Titan, also there was no $300'000 lost in a mega battle. That is just the press hyping this event.
You can buy gametime with $ which you can convert into ingame currency if you wanted and hence the conversion rate of $4000 for a Titan. But practically no one with sense does this (unless you are some rich kid who spends his daddy's allowance into gametime cards) I am pretty sure that those $300'000 ships where produced by ingame currency and not with real money.
You can play EVE for free if you make enough money ingame and then buying a gametime card with your ingame currency every month.
Vip (EVE player for 10 years)