Audrey,
Don’t replace your ink cartridges just yet. The main problem with leaving your Epson all all the time is that the print head is exposed and the nozzles can dry out and get plugged. When it’s turned off, the head parks on a landing pad where the heads are covered thus minimizing the problem. You can use the Epson nozzle check tool to verify whether or not you have a plugged nozzle. Since you already cleaned the nozzles, this probably isn’t the problem though. Inks can go bad when very old but if you are using your printer regularly I doubt that’s the problem either.
If your monitor is calibrated (and you said it was) and the image looks correct on the monitor, you should be able to get pretty close to that when you print. If you can’t the problem has to be related to the printing process. Mark’s recommendations are sound.
I would not use "same as source" for the printing profile. Some people get perfectly satisfactory results that way though. Selecting that will effectively turn of Elements processing of the profiles. If your printer driver color management is also off, you have no color management processing at all. This option is usually used if printing an image that has already been converted for print (not likely with Elements) or if you are printing color swatches for use in a printer calibration process. It isn’t intended for normal use. If you have established a profile for your specific printer and paper combination you should use that.
When you click the print button, you should get a print dialog box where you can specify the printer. Click on the properties button to examine or change the printer driver options. Epson drivers usually have a "custom" mode, select that and click the advanced button to set color management settings. If your driver doesn’t have this, look for something similar that will let you set the color management options. There should be a selection under color management that says something like "no color adjustments". select that and save the settings. Print driver color management should now be off.
If your selected printing profile is correct, you should get decent prints.
If you haven’t looked at Ian Lyons site, you probably should:
http://www.computer-darkroom.com/ps7_print/ps7_print_mac.htm He wrote this for photoshop but much is directly applicable to Elements.
Bob