My engine had done 113k, so I guess it comes down to whether a new or rebuilt bottom end attached to a 113k top end is better than a lower mileage engine swap? I didn't know, but figured that mixing top & bottom ends was unrealistic, but if a swap was likely to be a better option than a rebuild then I wondered what my options were if I could find some patience & an extra couple of grand. Google seemed to suggest sufficient precedent that physical engine bay space was available, so I was curious as to what else would be involved. If it's as simple as the 3.8 engine bolts in, then remap to the Boxster, then the costs don't sound like they'd be as scary as they would be if say the exhaust didn't fit or other oily type issues I don't understand... I remembered that Gibbo had put GT3 bits onto his C2S, but didn't know the expense involved...
Those GT3 parts were mainly suspension, the only GT3 part on my engine is throttlebody as Porsche did that at the factory with X51 cars. You need to check if and when you put a new engine in if putting in a 3.8 will you need the ECU, EWS, ignition from matching car etc or can your ECU/DME simply be updated. Also will your Boxster exhaust fit, as already said this could be huge job. Your far better off ringing Hartech and asking them for what options you have available from basic cheapest swap upto a more powerful engine with uprated IMS and liners which won't score.
When I was last at Northway; the owner (Ray) was telling me that Porsche have dropped the prices of their engines significantly possibly because more people are having them rebuilt rather than buying new engines.