Several aspects involved in answering that question ranging from true interest to economics. Those of us with true interest will make time for this hobby and seek out different recipes to try. That runs headlong into economics. Most of us cannot afford to
buy that much stuff. Basically, DIY is so much cheaper than B$M
juice. And, a lot cheaper than internet purchased
juice.
I suggest you first look over this DIY forum including the recipes. Make you text file and copy and paste the recipes you think you will want for later. This should be an ongoing thing...
Then, look at
Wizard Labs for your supplies. There are other companies out there, but these folks seem to be the best (my opinion). Order just a few flavorings, and a smaller amount of vg/pg/nic.
Read, read, and read for the next week. Follow the links in the various threads. Ask a few questions here. Then place your order.
That's what I did.
As you learn, mix, and relearn, you will place more orders and do it smarter...
Good luck - Welcome to my hobby!!