Welcome to the forum
Trust me, it's not the maintenance, it's the start-up costs! A tank's the cheapest part of the entire system most of the time when all is said and done! Maintenance costs for my planted 55 gallon
(don't have costs, but here are the items):
Water - minimal cost per gallon from the tap
dechlorinator - very cheap in the larger
size bottle, literally less than $0.25/week
Electricity for canister filter - @ 9watts, minimal
Replacement items for Eheim 2215 canister filter - about $40/year at absolute most, probably much less
Heaters (2x 100 watt) - ??/year, right up there with the tank lighting in terms of electricity
Lighting electrical use - LED's, minimal $$. T5HO lights, less than 70 watts x 8 hours/day
Plant fertilizer - not needed with plastic plants!
Fish food - depends on what kind of food (flake, frozen, freeze-dried, live) and how many fish
I think that's my consumable maintenance-item list. My big financial hit was the start-up cost for hood, filter, substrate, fish, plants, and then medicine to fix what I screwed up by rushing my tank's set-up! Daily operating cost is actually really low once established.