After ~24h, import on my local VM is at 17.8% and the importing speed is constantly going down. It started at 320 items/min but right now is at 271 items/min and still melting (melting quite slow, but still). We can assume it will crawl at 45%, just like on production machine.
It also turns out that i've made a wrong assumption few posts back. "the longer it runs, the slower it gets" should be changed to "the farer it gets, the slower it works". I can say that because even with @gerhard fork (which totally improved skipping part time), import is super slow at 45%, it has nothing to do with script run time. It seems that it's somewhat related to the amount of posts already imported/skipped. Does that make any sense? Maybe that would be a clue for somene.
ps. i'm gonna send a db dump to gerhard