I feel quite confident there is guidance available that could direct you to having the long term shored 834P up and running for less that a $100 if like for like components are selected, extend to $100-$200 if a upgrade route is wanted and depending on value of Boutique Parts selected, add another $100 if Copper Foil Cap's are wanted.
If EE work is not done by ones own hand a further $100 will cover the support of a professional EE. A enthusiast EE with Phonostage and Valve experience will find this refurbishment quite unchallenging, it might be the cheaper option if help is needed.
Is the weighty and loose bass produced by this model still your preference after a 15 year hiatus from experiencing its influence.