That depends on the strain
Dropping $100 for an established strain pest free
Well worth the price of admission
As opposed to thousands of dollars in seeds with few actual keepers
That's crazy, clones are $4 and have been $4 here for at least 20 years, they were maybe up to $6 before that. There was a time where you could buy plants already vegged for 2-3 weeks for $25.
As for pests depends on the cloner. Some will have some wont.