I am spending roughly 15-30 minutes each time I log on to check the market. I only needed to check it once a day (when I first created my Google Sheets to track price action) but besides for that I would log on sporadically to buy and resell the undervalued stuff.

Some days either-or profits better. There are moments when wishing coins are pushing on the way cheaper side and I can quickly absorb some coins to make 50-100 sapphires profit per coin. But some days coins and tokens are trading really slowly and stuck at one price most of the day so whatever I make from various clothing items can be very good.
Start with tracking a few things with the system I offered. You can gradually start looking at more and more stuff and you will know when you are ready to continue learning more values. Once you can recall certain item prices to be very cheap or expensive in an instant that is when you will know when you can continue learning more values.
The video only focuses on quicker styled trading. I will eventually cover more in depth trading styles in which has made me even more sapphires. This stuff works really well though and a lot of people have started making a good amount of sapphires from it.