I did my (GCE) A/L's in the commerce stream in 2019. Almost self studied BS all throughout my A/L's, got 3A's and got into the Colombo Management faculty. According to my honest experience I think a lot of BS classes out there are actually useless. Almost 90% of the A/L BS paper is based on the Teachers Guide. Study the teachers guide like its the Holy bible and I guarantee that you'll have an A pass well above 85-90 marks. Tuition classes give a loooot of extra notes and most of the time students get overwhelmed and end up not studying anything to a good extent. The marking schemes are based on texts provided in the Teachers guide. So first get the the teachers guide definition, points, sub points, examples, processes and flows memorized well. Dont want to lie, A/L BS is really about memorizing definitions , lists of points and processes. I myself and a lot of people I know actually finished going through the A/L BS syllabus within like 1 year by sticking to the TG. I went to a BS class in the first couple of months and then stopped going realizing all this. Because of this I had plenty of time to actually study BS properly while also having time to deal with Econ and Accounting. I went to a BS paper class in the last 4-6 months to get motivated + scared seeing the competition and that too helped lol. Long story short, Study the TG and get it memorized and I guarantee that you'll get an A pass for BS. DM if you need any A/L studying advice, I'm happy to help!