You don’t have to do a linear regression to see that LEGO sets generally run about 10 cents per piece, but its good to know that the data backs up this perception.
What’s also interesting to consider is the cost per stud on bricklink. This is not linear at all. A 1×1 plate with one stud might cost 5 cents but a 6×8 plate with 48 studs only costs 15 cents. If this were linear, (assuming the y-intercept is zero,) the 6×8 plate would cost $2.40 and a 32×32 baseplate would cost fifty bucks!