After you turn it on, hopefully there's still ink in the carts for run a nozzle check. You'll need a couple of sheets of 8.5x11 paper.
First, I'd take each cart out and gently shake them to get the pigments distributed back in the liquid. Put them back into the machine and run a check.
If the pattern prints all 8 colors print, you are fine. If any color doesn't print or there are gaps, run a cleaning. If you have enough ink, you can run a cleaning cycle several times. Hopefully you won't need to run a super cleaning cycle since they run lots of ink and I think will wear out your head faster.
Recently, a 9800 went for about $1200-1300 on this list here in Northern California. The 9880 replaced the 9800s with an improved head and the Vivid Magenta ink update. The 9890 goes one better with the auto-changeover to matt black and the rotary cover. However, you pay a price for convenience and IMO, the photo black ink still looks nice on matt papers, though just a little less rich. It isn't bad, just not as rich as the Mk.
While you are at it, check any other component life you can through the panel display. Newer Epson prints don't seem to have this display, though there may be a way through the Epson control panel on your computer.
Good luck and enjoy the speed and large prints you can now do! I got my first 24 inch printer in 2005 then my first 44 inch printer in 2007 and never regretted the purchases since each, in my case, has generated enough print sales to pay 'em off in little time!