From R’ Sears book:
“Otzar HaPoskim, sec. 87, cites Teshuvos Imrei Shefer and Binyan Zion to the effect that one may not cause tza’ar baalei chaim for the sake of financial gain, a position supported by Teshuvos Yad HaLevi, Vol. I, no. 196. However, other authorities permit tza’ar baalei chaim for financial reasons, seeing this as a form of tzorech adam (human benefit); see Chasam Sofer on Bava Metzia 32b, Noda B’Yehudah, Vol. II, Yoreh De’ah, no. 10; Pri Yitzchak, Vol. I, no. 24; Yad Eliyahu, Kesavim 3:5. While cautioning that one should conduct oneself beyond the letter of the law to avoid causing tza’ar baalei chaim, the late R. Yitzchak Weiss of Jerusalem’s Eidah HaChareidis agrees with these latter authorities in Minchas Yitzchak, op cit.”