"Why, when land prices, density of population, and demand on amenities are vastly greater in a place like Fingal than in say Donegal?"
Actually, this is not logical. The cost per capita of providing services should be lower in an area of high population density.
"I know land prices may be greater in fingal, but i was born and bred there, so why should i have to pay a higher penalty for the privilege of building on my family's land which has been in our hands for generations"
There is likewise no logic to this, unless it were to be argued that those previous generations had already paid for the local services; (but they didn't).
It might not necessarily be a bad thing if levies were to be allowed to creep up. The price which a developer pays for land is mainly a funtion of the cost of acquisition, cost of development and sale price. Every extra €10k on levies pretty much feeds into €10k less paid to landowners. As the money which landowners get is a state-generated windfall, it could validly be argued that there is nothing wrong with the state appropriating the benefit of the windfall to itself.
My view on this issue is somewhat tempered by my view that the agencies of the State - and particularly the local authorities - are not good with money, and perhaps anything which gives more money to them is to be abhorred on principle.