I think you can spend as much or as little as you like on vaping.
The first two years I spent an average of about $350.00 USD per year, that was literally for everything, storebought ejuice included.
The third year I spent about $2,100.00, the fourth, although I quit vaping in largest part (just vaping some zero nic a few puffs a couple times a week these days) I spent about 45 dollars or so.
For me that is a 4-1/2 year savings of $6,650.00 (cigarette prices are cheaper here..)
All that savings, and I have all kinds of mods and atomizers, rebuildable and other, a stock pile of nicotine in my freezer, flavorings, PG and VG etc.
Even if I vaped daily I'm set for spending very little for years..
So yeah, vaping is definitely worth it from the financial end.