Is it an entry level Porsche of today an entry level sports car? No way! If you get a Cayman, it might be their cheapest model offering. This doesn't mean that it is an entry level sports car. It is a very capable sports car. It just focus more on handling and vehicle dynamics comparing to the biggest 911 siblings, but definitely not an entry level for track days or sports driving and the like ...
Same can be said about the Porsche's of the past like the 924's, 944's and 968's. The majority were again 4-cylinder NA engine cars. Were they entry level cars? Even by today's standards they are not and they are quite capable:
(Continental's test race track)
If Porsche cannot offer nowadays a cheaper option in their model range the way they did in late 70's, 80's and middle 90's and Subaru can offer it, then it is an issue of Porsche. It is not an issue of Subaru or that the 86/BRZ is a "cheap" or an "entry level" sports car.