Just to throw in my two penn'orth, I use an Epson R2400 A3+ printer, cost of consumables is about the same, however I cannot purchase cartridges for it here in Singapore, so I bought a continuous ink system for it from Inksystem. The equipment is Korean in manufacture, but they have world wide coverage, my unit was actaully sent from Russia! check out their website at Inksystem.com
I have always had problems with third party cartridges in the past not delivering the correct colour and was expecting similar hassles with setting up this system. It arrived with Ultrachrome inks including the optional matt black ink, 9 colours in all. total cost US$58 for the hardware and US$117 for the 9 inks.
A complete set of cartridges [8] oem, costs about US$125 and has only 8 cartridges of 13ml therfore cost per ml is US$1.20. The Inksystem ultrachrome inks supplied 900ml for US$117 giving a cost per ml of US$0.13. Approximately 1 tenth the cost.
as I said I have previously had bad experiences with third party inks but I fitted the system which took 20 minutes and then ran a test print - astonishingly almost identical to the Epson Original ink output! A minor tweak to the printer ICC using my spyder and the output was spot on.
If your printer was purchased locally in Singapore go to the shops in the HDB block opposite the FU LU SHU (sp?) and OG shopping complexes where there is a specialist CISS supplier, however I have not used the inks he supplies and pigment inks are hard to get here if you use them. The hardware looks very similar, my problem was getting matching hardware for the 2400.
If you are considering doing a lot of prints, or just routine numbers then this is the way to go. Inksystem will mail worldwide for a very reasonable cost and if you really need bulk ink will supply in 1 litre units - that is 9 litres of ink - for US$757 US$0.09 per ml.
I know that this is discussing ink cost only but ink cost is a major component of the running cost of the printer.
The other thing you should invest in is a waste ink tank. this connects to the pipe that drains ink from the sponges under the printhead used for the cleaning cycle which is directed to a sponge inside the printer (cause of the black edges you mentioned) when this reaches capacity it can hold no more ink and leaks all over the printer or in the case of Epson printers after a certain number of cycles the printer shuts down and requests a service to change the ink pad. by using the waste ink tank, fitted externally, this problem then never occurs. A software utility availble on the net is used to reset the printer waste ink counter and then the printer continues normal operation. As the waste ink is being diverted out of the printer there is no more black edge problem too! Note that this does require you to open the printer up to connect a new pipe to the existing drain pipe. Instructions are provided.