Flight- outie gets permafly most of the time, which greatly mitigates the need for flight potions.
Other preps - gathered via secret sauce or from other locations (e.g. barovia gargoyles).
Can sometimes get haste staff by vandalizing once your skill % gets up there.
W/ my ranger, I think if I'd had to buy all my haste staves (as opposed to using the secret sauce method) I would have ended up using haste less often than I did. As it was, it seemed like I was able to haste myself *almost* every time I got someone snared.
Evil outie ranger gets: secret sauce stuff (both kinds), around 100 extra hp from strengthen, whatever +dam you get from strengthen weapon (maybe +6 at hero?), the +dam from ignite and (if you're lucky) insects.
Biggest drawback = having to raid/retrieve.