One of the things that has puzzled me about a "performance" car such as the Boxster is the lack of an oil pressure (O/P) gauge. That being said, has any of the "mechanics" checked the O/P? There are lots of things that will squeal (alternator, A/C compressor, water pump, etc) not to mention the belt. "Ticking" could be an O/P related problem and/or something internal. Remove the belt that drives the above components - does the squeal go away? Does the ticking go away? If it does, you can concentrate your search on one of them. Assuming it does not... do you have good O/P? Can you get the car on a lift? If so, use a long-handled shaft (i.e., screwdriver, etc.), place one end tight against your ear and probe the engine w/ the other - you can hear most everything going on inside. This should get you to an area close to the source of the ticking. Do this on top and from below.
Re a replacement engine (worst case senario), I would search for a salvage yard piece. My guess is that would save you thousands. These cars are not brain surgery so let's not get all "anal" about them - they are, in the end, an internal combustion engined automobile. Although Porsche has done a relatively poor job of designing/fixing the RMS problem, other than that, it seems to me they should be capable of doing daily service for 100K miles+ without anything but regular maintenance. What else would anyone expect out of a $50K car??.... I'll look forward to your report.
