The only thing I like about the Bo over the 210 is the cowling.
For $100k you can buy a early 210 (1964 to 1966) decked out with 4 (plus two kiddie) seats and wing struts and pocket $30k to $40k or a later one (1970 to 197? in decent shape with 6 seats and cantilever wings.
The 1964 - 1966 have the highest service ceiling of an NON-turbo plane I've seen at 21K feet.
You can install an anti-detonation STC and run 91 octane mogas in many C210. (210,A,B,C, G, H, J, K, L, M, N )
http://www.airplains.com/index.php/news-updates/information-articles/121-anti-detonat-injection
I believe the 6 seats started in 1969 with the K model. 6 seaters have a round tube landing gear leg. These do not have the saddle cracking issues that the 4 seater flat spring gears do. Some of the very early round tube gear 6 seaters also have a 12 volt electrical system avoiding spendy batteries. (They also have an engine driven hydraulic pump) I believe there were a very few serial numbers that are 12 volt have the electric driven hydraulic pump and 6 full seats.