I have never had the impression that the cannery is the grand total of their assets. I think it reasonable that most of their money is tied up in various investments.
I don't think it odd that a New England family would live frugally whether they had scads of money or not. We aren't talking nouveau riche out to make an impression!
I don't think they are rivalling Onassis in wealth, just that they have a good amount invested and a supposedly profitable business. (Whether that is realistic or not!)
I don't have a problem with that part, the family has been wealthy and continued to do well. What I have a problem with is that they ran this huge mansion for YEARS and YEARS with only one cantankerous handyman. Ok, obviously, noone has cleaned the closed off wings or the basement for a heckofa long time. But, we are supposed to think Lizzie cleaned the place from top to bottom in her cocktail dress? Or, choke, sputter, think that CAROLYN lifted a finger to help her?? Oh, I KNOW, Roger was always happy to pitch in and run the vacuum! Uhmmm, right.
The other part I find hard to take is how well it must pay to be a supernatural creature. We never see Barney or Wolfie boy rifling through their victim's pockets and emptying their wallets! Ok, I know that Barney is explained by the countless number of family jewels that he had hidden away and now he can live forever off the proceeds. (Can't you just imagine Joshua's fury at not being able to find them?!) Not believable, but at least a flimsy pretense in my book. But Chris? He is presented as middle class, and no fortune to be inherited as far as anyone can tell. But he certainly doesn't work.
At least the Rev. Trask had a job!