The curse of the lower price Epsons is a high probability the printhead will clog.
But quality will likely be OK. But the Canon MP780 is based on the ip4000 printer engine
and that also gets universal raves on quality and durability. With a user servicable printhead that
can be removed and cleaned in the super remote possibility it ever clogs. Not so with the Epson thats factory service only.
But its on per page ink consumable costs that the MP780 shines. Slightly better than the best Epsons
and light years ahead of HP's and Lexmarks. Since the MP780 uses the easily refillable BCI-3&6
cartridge family, OEM cartridges offer low cost printing-----but pair them with readily available third
party cartridges and you easily get below a penny a page for B/w text.
Beware of the newest Canon's that use the new chipped cartridges in the BCI-5 and CLI-8 cartridge families. They still offer the best consumable costs of any printers using OEM ink but you can forget using third party cartridges.
I have a MP 730, kinda similar to the MP 780 in that it can print, copy, scan, and fax. Given my druthers I would rather have the the MP780. But I got a hecka of a buy on my MP 730 on the used market----and its an awesome unit.
Worry less about initial purchase cost------get a unit that does what you want, will be cheap to operate, and will last.------and at $200. I would recommend the MP780--and check that it may be office max not Staples.
You can find cheap printers that will print, copy, fax, and scan for maybe $75.00 less. If you do much printing that $75.00 will be out of your pocket buying replacement cartridges in a hell of a hurry.
But don't take my word for it---google Toms hardware guide, nifty stuff forums, steves digicams, or look at the April /05 issue of consumer reports.