I'm pretty interested in buying the D&D Starter Set as a way to get introduced to D&D and being a GM/DM for the first time. Ever since I discovered this RPG Stack, I have read a lot of D&D Q/A out of curiosity and I really wanted to try it out.
I have already played a bit as a player with a group of friends, and I'd like to DM for this group as I'm a bit shy and I know them pretty well so I can anticipate how they will act and can react better to this.
What I'd like to know is: Given a party of moderately experienced players (a party of about 4/5 at maximum), and considering the information above, roughly how many hours of play can the starter set campaign be expected to last? (at a minimum, without including side quests/jobs, with fights going well, etc...).
Prior experience with the starter set would be really appreciated.
As a note, I've also asked a second question here about transitioning from the starter set to another module.