It's fine to make a "token" contribution to your SSPX Mass center.
But unless you truly believe your SSPX chapel's existence is in jeopardy, it might be just as good to give your PRIEST a donation directly. Then he gets to keep it, and none of it goes "upstream" to Bishop Fellay.
Don't forget that the SSPX chapel is NOT your local parish, and you are under no obligation to give generously to them. The commandment is to "contribute to the support of the Church" but the SSPX is not the Church; only one branch of it.
If you want to give a traditional tithe (10% of your income), you should find a worthier cause to give most of it. http://cathinfo.com/resistance
If you support any Catholic priest or organization
you are fulfilling your obligation.
In the old days, you could just put your weekly donation in the collection basket, and the Church would take care of allocating it where it was needed.
Today, though, Trads need to be careful who they support, especially who they support with guns blazing (large donations). Careless donations are why so many good Trad priests lack funds to do more good work, while various bad Traditional organizations (even de-facto cults) have tons of money.
The Trad faithful need to be a bit more discerning about who they support. We need to cast our dollar "votes" on solid, objective PRINCIPLES -- who is objectively doing good work for the Catholic Church and for souls, and who is doing a little bit of good, but causing a huge hindrance and stumbling block for others?