I agree. I'd like to add something form experience. Montanes are only slightly trickier than lowlands in most regards. That includes vitamin and mineral balances and humidity. They are BIG differences, and if you can deal with them, they're not hard, just different.
I never reccomend a montane as a beginner chameleon, simply because of the really difficult aspects of them: Temperatures.
Temps are much harder to get right than you'd expect. Especially if yo've already got lowland species. Put it this way: If you're going to keep a montane species in the same room as veileds, beardeds and of all thigns, a uromastix, it's gonna die early. the heat itself might not do it, but it'll cause issues in the long term.
I had this happen with deremensis, one of the more "warmth tolerant" montane species.
In my animal room in the Raleigh area, it just din't get cool enough at night. They all died at around 2 years of care with grossly fattened livers. Temps never got cold enough for them to go through a cool-down period. That period is vital for their metabolism - not cool down/fasting period, and the never lose their fat reserves.
Montanes just do better in a basement. If you cannot get the day temps around 75 degrees, and if you cannot get nighttime temp drops in the 60's, I'd forget abo montanes. It's just not worth it.
I dont' want to discourage you. If anythign, montanes are underappreciated. I encourage you to continue your research (which you are clearly doing well in advance of purchase). See if they can fit. If you've got a basement to use, or a cooler room, I'd go for it.
Montanes are a heck of a lot more interesting than the other species. The problem is most people (me included) like to keep them all in the same area.
Aside from a MANDATORY cooldown and fasting over a couple months, I find deremensis to be the hands down easiest species to keep. They always eat from your hand, they are much less sensitive to vitamin imbalances than other montane species, they dont' require the nail-biting paradox of a heat lamp and cool temperatures... a tube is all they need for most of the year (only after cold nights, they will bask, and gravid females will bask too). They don't eat too much, they're big, not very shy, and will almost always eat from your hand right out of the shipping container.
They are not easy to breed. Deremensis have a reputation for being weird and inconsisten in behavior. I think it has to do wiht seasonal temp cycles. I've let them have a rough winter, barely eating for the coldest months, and they are perfectly behaved animals the rest of the year. When I had them at constant (70-80degrees) year round, they'd go through fasting periods of 1-2 months by themselves - especially the males - it drove me nuts.
Now, after they warm up post-fast, they never refuse food.
my only gripe against rudis: tiny tiny babies. Man those babies are tiny. very small and not super fast growing. that means small prey for a long time. Veileds are on small insects for a week.