If I bought tracts with my tithe money? Perhaps this may be a good idea as if I gave money to the local church they are gonna use it anyways and what they may use my tithe for I may not endorse. If I buy tracts with my tithe then I know for certain that I am donating to the Lords work and not donating for causes I do not support.
Will your church provide funds for Bible tracts?
If you are a member, then you have a voice in the finances of your SBC church. Have you spoken to the pastor or members of the finance committee?
Does your church share your vision of evangelism? If not, you may want to consider joining another church which emphasis evangelism in a way that you do.