The Provari is expensive, but it's not a throwaway PV. There's repair service available at Provape for reasonable prices and they will upgrade your current model to the next version. Right now, folks are getting their V1 upgrade to V2 electronics for $20 and that includes return shipping.
I don't have a Lavatube, but it was on my short list of finalists when I was shopping for a VV tube mod. Service and workmanship won out. The realization that a Provari is equal to about 4 cartons of cigarettes figured in nicely, also. The Provari is a heavy PV at 9 ounces, but it's reliable, repeatable, and consistent in the vape you get.
It's use of 18650 IMR batteries was another consideration. IMR probably doesn't have quite the charge life of a Li-ion, but it can take more heat and heavy current draw without entering thermal runaway and that's important to me. The LT can use those also. I was also tired of pot metal threads on eGo batteries. SS threads will sacrifice the threads on the atty rather than wearing the thread on the PV.