If you're not going to be printing over 13x19, the other option is the P600 which is less expensive (and yes, smaller inks than P800), but you will still have the same technology in the printer that is better than the R2880. It's actually the replacement for the R2880. It really depends on your budget.
Also, I would probably steer away from refurb models since they will most likely have a used print head in it (if it was replaced). The warranty docs don't guarantee a new head if it needs one, so there's a good chance you may get one that may fail you soon. Not saying this will happen, but I had a customer that went thru 3 replacements (P800) and each had an issue. If you get a new one, it's a brand new unit and head with the 1-year warranty, so you know it's new.
If you decide to repair an older (discontinued model), there will be a time when the parts will be discontinued as well so to us, it's not worth it if you'd be replacing it in a time frame anyway. Get a newer model so it has the part readily available and you don't have to wait for something to come in. Not that we want customers to buy a new printer, but just think of how old a model is and what parts "may" be available in case of a repair comes up.
Hope that helps.