welcome to the yoga forum. We look forward to your continued contributions in the community.
On your first point, it is best to go and try and determine these things for yourself in your living. Finding sites with yoga classes is as easy as using a search engine, so you don’t need me for that.
Online courses, when they are well taught, incredibly clear, and inherently safe, are partial contributors to a robust yoga practice. They are not, in and of themselves, a robust yoga practice. The interaction between teacher and student during contact hours is quite critical to the growth of the student.
As for cost, generally speaking one gets what one pays for. When a student ONLY receives the teachings without an exchange of energy (in some cases currency) an imbalanced landscape is created. This is the same in any relationship and can be easily vetted if one interacts with their spouse or partner and ONLY takes (or ONLY gives). The erosion is fairly rapid.
I suggest that students look at the value side of the yoga equation rather than the expense side. Instead of looking for a discount class, look for a class of regular cost that offers immense value in the transmission of the teachings. Pay $15 but get $100 of value. Or stick to the norm and find an $8 class which gives $5 of value.