continuous feeds are specific to each epson, they cost between 30 and 60 pounds then u need to buy the seperate inks, some epsons can't use them, what model epson do you have,
you can also refill epson cartridges if you dont want a continuous feed but you need a chip resetter, you could also benefit from stopping the in built cartridge counter cos when you have put in a certain amount of cartridges your epson will shut down and tell you, you need a service.
continuous ink systems have a bay of cartridges which slot into where your normal carts go then have a feed of plastic tubes which leed out of your printer to refillable pots, you just top them up, never used them myself but i sold plenty when i was in the game.
derek
ps, don't go for the cheapest bottles of ink, there usually inferior and block your heads.