For a running, cosmetically good /5, $3950 is actually quite fair. Looks like he has a toolkit and an original manual as well, which are a few hundred purchased separately. The R60s aren't quite as desirable as the R75s. And the SWB bikes aren't quite as desirable as the LWB bikes. Hard to tell if it's LWB from the photo. '73 was the transition year.
If that white toaster tank doesn't have any dings, is original paint, and the chrome is in good shape, it could sell for $700-$1000+ on its own. I just sold my completely dinged out toaster tank for 300 euros.