Hamaji is asked if his house ever recieves year-end gifts. He says that they get dried shiitake mushrooms. His friends express surprise. One of them says "it's not bad but..." and then Hamaji says:
"It's not bad. Our mother ends up really happy" (my TL attempt)
I'm assuming 喜んじゃって is the て-form of 喜んじゃう which is a contraction of 喜んでしまう. I don't understand why it is in て-form or what the meaning of さぁ is. What is this てさぁ ending all about?