There's not really anything to invest in. The unit has pretty significant yellowing, the badges are all stripped, and the keyboard is shot. Even with the printer and III drive, I'd still call it $50 dollars over-priced, especially with the logic board sight unseen. The only way I'd consider it was if it was a RevA, one of the original 14k from before the logic board revision.
A new keyboard replacement, which does come up on eBay occasionally, is gonna cost you another $100 - $150. A new Monitor III will add another $100 to the tab. As everyone pointed out, there's no software or manuals. I bought one about two years ago, a RevB in working condition with all of the manuals and papers, and a whole box of software for $500.
If it were me, and the Apple III is my obsession among the 6502 family, I would pass on the deal and wait for something that has more to offer.
