Honestly I am not friend of 1k renewals when it comes to my domains. I buy personally only domains which has standard renewals, and there are some opportunities even today, but lot of research is needed to acquire good name with standard renewal. You can either hand reg these types of names (these days it is already almost impossible, but in 2014/2015 this was well possible, as registries were also just starting and did not have experiences which they have today), or you can drop catch, or buy from other domainers, mainly from those with poor budgets and few days prior renewals.
But one can not say that 1k renewals (for example) are huge..there are some people out there for whom 1k are peanuts, 10k are peanuts, 100k are peanuts..they can acquire such names and trade with them. But most people can not , and can only be profitable when they are getting good names for standard renewals (ideally around $20-30/year).
"Assuming that new extensions are going to rise in value like .com sounds like wishful thinking. Especially when the scarcity has gone. The dynamics at play are not the same."
I do not care if new extensions as such are going to raise in value or not. I care if particular combo (keyword1.keyword2) will rise in value. You can have only few good combos per most of new extension, remember that
