Low cost ink

Now I have finished my website I was shocked to see that many ink suppliers charge "huge" amounts of money for Epson compatible ink cartridges. When I built the new site Viva Ink I tried to remain very competitive (or so I thought). My aim was to deliver Epson Compatible ink cartridges for less than £1.00 each. However, having checked out the "big players" I note that because they are at the top of google they can charge in excess of £6.50 each. I cannot understand how they get away with that inflated price and why my rankings are not moving up google. My compatibles are of the highest quality, same day dispatch and come with a100% guarantee. So the morale of the story, good quality ink at a fantastic low price which is arguably the cheapest on the Internet or the high street still does not equal sales? So now what.....advice more than welcome.