I suspect that by the time you add up the parts prices you'll be out of pocket by a long way. And it might even be that the computer doesn't want to deal with it. My first call would be to a competent workshop manager to see if the upgrade is possible. Then I'd run it past the parts guy to see if I go home happy or not. The trouble with parts is that they sell them individually and not in a full assembly at a cheaper price.
I've no idea how much extra the ABS model is when new (here in Oz all bikes have to have it) but that price difference won't be repeated on a used bike.
In short, no.
Lots of Lil bits involved in that that will add up let alone the expensive bits like ecm, harness and sensors.. the labor involved would be astronomical if not DYI and even if DYI lots of time..
Plus all of the "unforeseen" that will no doubt come along while doing it, just wouldn't be cost effective..
Other than getting an insurance discount for having it, I could care less if it did. I guess if you grow up in an era where you have it and rely on it, maybe it would matter to you. Riding a whole lot of years before it was even an option means most us got used to using the brakes manually /Proficiently without. IMO ,I would just as soon have a less complicated system, and save 10 lbs too.