Only the front bumpers are sought after, along with a handfull of other parts - the roof module for example.
In general 129 are a very well made car and don't rust or fall apart like most MBs, another bonus is that many of the parts are shared with 124s which are still cheap and plentiful (for now).
the engine gearbox and diffs wheels interior and other bits, they would brake for 3k, but some models are sought after and better sold as complete car rather than ending up breaking if the engine is good order and low mileage IMHO.
i have a friend looking for 300 sl non 24v version to buy on low budget. if too many get broken then this means prices of the earlier sought after models will rocket!!