Sounds like an essay question
Here I'll have a go...
I would say that electric vs hydraulic/pneumatic is not the key differentiator in terms of price. Of course there may be some impact to prices of sub-components at source of supply like semi-conductors, CPU processors, copper, lithium etc. but the price that the end-user sees is based on;
1. How new is the component? If the part is recently certified, the sale price is very high and the spares price is astronomic - suppliers try to recoup their certification investment up front by amortizing the engineering cost into the price of the part when it's new, with a price vs time relationship that's a bit like a radioactive half life in theory. AOGs (aircraft-on-ground, stranded at the gate needing a spare) make the most money as these can be x10 markup because they are opportunistic - you can twist the arm of the customer if they're desperate.
2. How big is the fleet? As the fleet size increases, economy of scale begins to take effect and new/spare prices slowly comes down as sales quantities increase. When the fleet is small and the aircraft is new, the parts will be the most expensive. As the fleet grows, the parts become more plentiful (on the MRO shelf and in the factory) and the price begins to come down.
3. How old is the component / how rare is the part? As aircraft age and the parts become more scarce, and may no longer be produced, you reach the opposite end of the price bathtub curve, prices will increase again because the business case for making obsolete parts is worse to keep an old lathe in the factory to make that one spare 50 cent widget for Timbuktu airlines at a rate of 1 a month, for instance. You'll charge $50 for that 50 cent widget to justify it!
So, for example, constant speed drive generators may eventually give way to wild frequency generators if the 787 is anything to go by, but the legacy technologies still persist and subsequently so do their parts. The old style parts may well be cheaper than the new electric equivalents, but only because they've been in production for longer.
But then Imagine it's the year 2068 - your 787 is grounded because you can't get a replacement generator, because all the competition have gone to cold fusion plasma cannon generators, rendering the old 787 part obsolete - but a man in a shed in everett will overhaul one for a mere $1 million (after inflation, haha), this will be the reality of things.
New replaced old. New becomes old, old is replaced by new. Repeat.
I even invented a PTU for Eaton with an integrated electric motor/generator that doesn't bark like a dog for the A320 but I'll be damned if Airbus will ever use it. Dinosaurs like the A320 and 737 are sold in quantities too high to get meaningful systems upgrades. The 787 and the slightly more conservative A350 were clean-sheet exceptions that got more exciting kit from the parts bin, just to differentiate themselves to try to sell more planes. But beyond that, it's just good ol' keynesian supply and demand.
More-electric trends in aircraft systems will, in isolation show an increase in initial prices of aircraft avionics and electro-mechanical hardware, but so would anything else that was new.
If you separate the question from the more-electric trend/fashion, you're back to supply & demand bathtub curve product life cycle theory;https://www.researchgate.net/figure/Lif ... _233361808
That's my best stab at it for today, thanks for the brain food.