Rav Shach said you don’t even have to say Shkoiyach because you are giving him more than he gave you!
I find it hard to believe that Rav Shach would say that you don’t have to say “thank you” to someone when they give you money. Furthermore, I find it hard to believe that Rav Shach would allow someone learning in Kollel to develop an entitlement attitude as in “it’s due to me.”
The Wolf (who says “thank you” to people even when they are being paid to do their job.)