Exhaust $4-$6k 'A muffler for my '84 QV is $6200 at the dealer. Just the muffler in a box, not installed, no pipes, no dounuts, just the muffler in a box'
Disributor caps $250-$900
Front suspension $2k
Considering the average distributor job on a 9th/10th-gen Toyota Corolla is about 250-700 (higher side if an actual distributor is needed), then that's expected for a Ferrari.
I'm not sure how many different components are required for the "front suspension" in this discussion, but typically replacing all control arms, ball joints, toe links, tie rod ends, stabilizer bushings, and shocks/struts would run nearly $1200-2000 in any car or truck.
Of course this is on US dollars, and I probably would consider any old Ferrari a money and time pit as well, although since money isn't the biggest issue with the prospective owner. Waiting and tracking down the parts that becomes the real nuisance in this situation. I've heard that most 1970s-1980s Ferraris are actually kind of simple to work on, although like any car, there's always going to be weird repairs that take bizarre amounts of labor, which is typical of any car over 20 years old when it has maladies.
The upside with having a Ferrari 400 is that you get a Ferrari that doesn't turn heads, and only a few causal glances. Kind of stealthy, but that 3-speed automatic sounds like it would be pressed to do more work than necessary, and less fun. But it's different...