I own an M4 and have an M2 coming in a few months.
To me, it isn't about the price difference as much as it is the difference in the experience. The M4, IMO, is worth the price spread based on its additional capability, interior treatment, etc. So it's not a value issue. However, the M2 is more raw, more focused, etc. So, the decision is more based on the experience someone I'm after.
If they were the same price, I would still pick the M2 today because that's the experience I'm looking for at the moment. In two years, I might want the M4 experience again and, even if they are $25,000 apart, I'd still buy the M4 if that were the case.
The price gap ($30,000+ in Canada) is, to me, just gravy