You can't obtain 3,4-dibromothiophene by direct bromination (Br2, NBS or whatsoever..).
Thiophene is brominated by Br2 in a sequence:
thiophene --> 2-bromoTh --> 2,5-dibromoTh --> 2,3,5-tribromoTh, 2,3,4,5-tetrabromoTh.
tetrabromothiophene can be obtained in one step from thiophene in mild conditions.
3,4-dibromothiophene can be obtained by reduction/debromination of 2,3,4,5-tetrabromothiophene with powder Zn.
This is a common route to 3,4-dibromothiophene (in 2 steps), both steps are straithforward and can be done in common chemistry lab in a large scale. We did it in 400 g scale (max flask size needed ,3 l).
See as example: K.Araki, H. Endo, G. Masuda, T. Ogawa, Chem Eur J, 2004, vol.10, 3331-3340