Yep, eHomer, as for the ink pad on the ET-2550 it works a little different to the Epson photo printers, in respect that very little waste ink is collected, to long winded for me to explain here, but trust me I know about these things.
What you have to bear in mind is that the print heads are under warranty for 3 years or 30,000 pages (10,000 pages per year) which ever comes first, now that for a consumer printer is a lot of printing, and to put that into perspective the average consumer will print just 600 pages per year.
The rest of the printer hardware comes with the same 3 year warranty, so I would expect that if in 3 years you have not gone beyond 30,000 pages, the ink pads will still have some life left in them.
As for replacement ink pads, I think it could be a case of beyond economical repair, past a certain point, there are of course hacks, that can reset the ink pad counter, and kits to replace the pads, or introduce an external tank whichever suits.
To be fair though, if you get to that point with the ET-2550 you probably should be thinking of getting an Epson Work Force printer that comes with replaceable waste ink tank, Epson supply a kit for around £20 for such models, but then your back to using ink cartridges again, so probably best to dump the ET-2550 and buy another ET-2550.
The price of the ET-2550 will be at £134.99 from tomorrow, and may return to £174.99 during December, usual street price is £199.99