I have two Epson printers and one of them is the RX595. The only drawback to the Epson printers is that you do want to print at least a page or two about once every two weeks to help dispell head clog. That's really the only advantage the HP "might" have over the Epson. The HP ink cartridges have the print head built in to them. On the Epsons they are built in the printer itself. However, even on HPs or Canons or any printer, if you don't use them for long periods of time (a month and a half or more) the heads can get clogged as well, whether in the ink cartridge or the printer. Ink drys up or coagulates over time, just the facts.
That being said though I would go with the Epson hands down! I've had a lot of Epson printers starting with an old Color 400. None of them have ever gone out on me, I upgrade and give the old ones away. You take care of them and they go and go and go. Ink is also less expensive for the Epsons because the cartridges are simpler since they don't have the print heads in them. Also, over the years and today I notice the same major design flaws on the HP printers. Most of it lies in the paper transport path. Far too many moving parts that are unnecessary and fail over time. The paper path on the HPs is too twisty as opposed to the Epsons which are fairly straight through.
As for obtaining ink, you don't have to pay for the lable, Epson, HP or otherwise. Check out this supplier www.klassicspecialties.com. I have been using their ink exclusively for over 10 years in my printers and have never encountered a single problem. These are not cheap refills. (Never refill your ink cartridges yourself). The only difference between their ink and store bought brand name is just that, the brand name and fancy packging on the box. If you check them out make sure you read their policies, it will make you feel better about giving them a try. They stand behind their inks. You will be glad you did. Example = complete set for the Epson RX595 = $30.00 that's a far cry from $10 a peice, although I think they run a little higher than that in the stores! If you do decide to save loads of money by trying them out (you'll be singing their praises after you try them), be aware that when you load the ink cartridges you'll get a warning about compatiblity. Ignore this warning and choose to continue using the cartridge. That "warning" is a marketing ploy. Epson is just trying to sell you ink at inflated prices.
(There is a continuous flow system available if you think your going to print that much. It's about $30 for the system itself, but I have never tried it, so I can't personally comment. I've seen it in action and it seems to be ok, but I don't need it).
SPECS
Mother Board: Gigabyte GA-M57SLI-S4
Vid Card: Sapphire Radeon X1950PRO 256MB 256-bit PCI express x16
CPU: AMD Athlon 64 X2 3800+ Windsor
Power Supply: Antec earthwatts EA500 (500W)
Misc: Arctic Cooling Freezer 64 Pro CPU cooler
2 GB Gskill memory
Western Digital 250GB 7200RPM SATA HD
Plextor 52X CD burner IDE
OS: Win XP with SP2