I'm not sure I really buy into the whole maintenance cost angle at least in the long term.
If you go to Fir Park or travel around the country you'll see that the Taylor report era stands that were built in the 1990s are not in the greatest nick. That suggests you have maybe a new stadium life time of about 25-30 years before you get back to square one. And it's not like new stadiums don't have any maintenance costs either, even if they are reduced you have to factor in the redevelopment costs along with rising maintenance costs over two or three decades and then what do you do in 2050? Build another stadium? Redevelop the existing one? It's a repeating cycle and I think it's even debatable if we would have paid off the debt of building a stadium over the sort of time period.
However my main objection is that Fir Park is Motherwell FC's spiritual home and if you take that away, for me anyway, you don't have the spirit any more.