It depends on what you have now, and what you are trying to get out of vaping.
My daughter and I quit smoking, cold turkey, around 9 years ago. We could not afford for both of us to continue smoking, and neither of us wanted to be the one to continue smoking and tempt the other. Around 3 years ago, we found out that for my daughter to complete her graduate school studies for her Doctorate in Audiology and get a job in her field after graduation the best bet would be to move across the country, from Ohio to California. Considering that this is a total life change, add in the fact that my grandson has autism, and you have a donkey-ton of stress. Add in the fact the neither of us wanted to quit smoking in the first place. Yeah, we REALLY wanted to smoke. My daughter had heard about ecigs somewhere. We started looking into things, and wondered whether vaping would really work. We hemmed and hawed. My daughter finally broke down, and got us a couple of Blu disposables. Wonder of wonders, it worked. No more cravings to smoke.
We have gone from cigalikes to Evods, and could not be happier. We are still not smoking.
I am retired, on Social Security. The vape budget comes out of my income, after I have paid my share of the monthly bills, since my daughter and I share housing and living expenses. My daughter and her boyfriend are not interested in researching things - they only want something that works - so I am left to make decisions for 3 people.
At this point, we are all quite happy with our Kanger Evod setups, with Kanger single coils. As far as glass tanks go, we like Protank 2 Minis or Evod Glass. All our equipment uses the same Kanger single coils. I do not rebuild coils, but I am trying to learn to re-wick them. I do clean the coils, and get 2-3 extra uses from each coil before I pitch them. I have found several vendors that I trust and offer reasonable prices for eliquids.
All things considered, my daughter, her boyfriend, and I are in a pretty happy place right now. We are still not smoking, have several vendors that we trust and have reasonable prices as far as equipment and eliquids are concerned.
Everything depends on you, and what you want to get out of vaping. You can spend as much, or as little, as you want to get an experience that is satisfying to you.