One of the 6 laws of the church is that you must contribute to the support of your pastor. It doesn't say how much.
Catholic pastors can nag all they want from the pulpit and demand 10% of your post-tax income, but they can't withhold the sacraments from you for donating less unless they want to practice simony. But, even if you tithe, they still won't respect you, so why bother?
As far as I can tell, the tithing requirement is strictly Old Testament. Only temple Mormons and some Protestants seem to insist on it today.
Of course, those of means among the early Christians sold everything they had and pooled their resources to share with the less fortunate, but those days are gone forever.
My feeling is that these independent traditional Catholic pastors have no committment to you, so why should you make a big sacrifice for them? They could close their mass center tomorrow and move to Jabip, and there'd be nothing you could do about it. As a mere lay worm, you have no say in whether or not the building is sold out from under you, or anything else, for that matter. You're just expected to foot the bill until they get bored and move on.
Let people who can actually afford to give up 10% of their post-tax income tithe. If people who can't even affort health insurance put a dollar bill (or even a nickel) in the collection plate on Sundays and Holy Days, they've fulfilled their obligation as far as I'm concerned. (I usually reserve the nickle for when I'm really PO'D at what they've done!)