308's aren't too bad. Buy one that is running and as complete as you can afford. Projects (like mine was) can be treacherous. For example I wanted to do a basic tune up on my '78. Just basic stuff like plugs, cap, rotor, points (yes it has breaker pints ignition), and wires....well, there are two distributors and two sets of points in each distributor. Each set of points is like $60, the distributor caps are $500 each, the rotors are $40, the wires are $450 etc, etc. So instead of buying new stuff I went after all my old stuff with a nail file and cleaned any corrosion off the contacts. I did some research and found a Fiat rotor that fit in place of the Ferrari one ($4 versus $40), I used generic Chrysler plug wires and adapted them to the Ferrari cap. Saved myself about $1900. I also figued out that one set of points is only used for smog/emissions testing. Since 1978 is exempt in Texas I removed them and used them as a spare set to replace the main set of points. Once we got past the carburetor sync'ing and setting the timing (you set the timing at ~5000 rpm on each distributor instead of at idle) I got it running pretty good. It makes about 240 horsepower (factory was ~210).
Timing belts can be a pain and the A/C is worthless (but if you remove the A/C the timing belt can be done a couple hours quicker. The previous owner of my car just had them done and I've only put ~5000 miles on it since I got it from him so I haven't had to worry about it yet.
I did have an alternator fail, but found a Fiat one that fit ($80 versus $1000). You have probably guess that figuring out what Fiat part fits instead of Ferrari is a real key to keeping it economical.
They are actually pretty basic cars, so working on them yourself is very possible. Ferrarichat.com is a huge help too.
Aaron