agreed, I went trough more weed when I still smoked only once a week. at that time I rolled my joints as fat as I could(some people thought I wouldn't be able to get the paper closed when I filled it, never weighed it myself but some friends estimated I put 1,5-2 grams in one joint)
those joints lasted 15-20 minutes, and after finishing one I would wait about 20-30 minutes before lighting another. did that only one night a week, so ofcourse really high everytime. I've even had some 'snow'(like a tv with bad reception) in my vision one time
I smoked that much because when I just started smoking my tolerance was really high, didn't notice anything my first 5 times smoking and the first time I actually noticed something was the first joint I rolled myself, pure instead of with tobacco as the times before(wich is common here), and mostly smoked myself(was with 2 friends, but they only had a few hits, and one of them smoked my ashcone... since it was so compacted by my bad rolling there was still some unburned weed in the middle), so at first I thought I would always need that much to get high
by now the amount I smoked in one night at that time could easily last me a week of heavy daily vaping, probably even multiple weeks.
a gram last me a little over a week now, but what I had back then was less potent, but it was also a kind of effect where it was easy(for me) to smoke more of it.
if I try to get as high as I got back then now I would just fall asleep, but what I had at that time was some sativa that would keep me awake and only make me a giggling pile in the corner of the couch, and cause some paranoia, but paranoia from weed has never been a problem for me, I actually enjoy it.
most I ever vaped was when I just began vaping, found some weed I didn't know I had, didn't weigh it but my guess at the time was 30 grams but at the time I had barely any experience with seeing certain weights of weed since I never judged quantity in grams but in buds or amount needed to roll a joint
that amount lasted me 3 weeks
after that my usage started decreasing untill stabilizing it's current point
My transition into vaporizing was similar... went from getting shitfaced on the fattest j's, blunts, and bowls I could suck down, to where I am now. Seeing my friends throw 2g+ of high grade into a wrap nowadays makes me want to go, "NOOOO! We could of all been high for days off of that". Of course, they don't understand. And also like you mentioned, I get high off way less product than I ever thought would be possible. All I have to do is load up what would have been "one big ass bong rip" into a vaporizer, and I can stay elevated for most of my day with no burnt out comedown feeling.