+1 to all of the above (i.e. good value but not a killer deal; quality bike in that condition wrenched by a knowing hand, beats the $700 you'd pay for an entry level new road bike by a mile ...), with an addition:

That 105 group from that era is incredible. I'd have to see the Shimano date codes to be sure, but it looks to be '86 or '87, and I have that group on a bike. The indexed shifting is good enough that apparently a few pros in that year put 105 on their bikes instead of Dura Ace or 600, because it worked so well (usually, innovation is "top down" i.e. the high end groups get the new technology first, with the next levels following by a year or two, but this was an exception ... the indexing technology in 1986 105 migrated to 600 and Dura Ace in following years). In addition, the SLR brakes have been regaled by none other than the late, and much-missed, Sheldon Brown as being possible the best single pivot sidepull ever made.

Finally, if you get the bike, give the BioPace rings a chance. Sheldon was also a huge advocate of these, and taking his advice, I ride them a lot. My 50 year old knees love them.

Short summary: talk the guy down if you can, but if you ride it and it fits, go for it.