So, if you are motivated and you have settled your goals (e.g.: I wanna take a certificate for the B2 level in 1 year, or I want to pass the exam at university or I want to be fluent in 2 years etc) for sure you don't need to take expensive courses (both online and traditional) or books, methods etc...they could help of course but surfing on the internet you can find everything you need, included someone who can boost your learning.
Given this fact, according to your level you might look for: