This appears to be from the Kumamoto dialect (熊本弁). In certain areas of Japan, there are different accents or dialects. Typically they change the endings of certain phrases. In this case, ばい seems to be equivalent to のだ/のです, which indicates reasoning. It could also be the equivalent of ぞ, which indicated a strong intent or for emphasis.

典型的な博多弁、九州弁で、おそらく深い意味はありません。口調の癖のようなものだと…思います。方言ですから、若い人も年配の人も使います 行くばい ＝ 行こう 行くぞ 作ったばい ＝ 作ったよ 作ったぞ

Ah~~~, I love how the Kumamoto dialect ばい sounds. Especially, 「よかばい、よかばい」which means something like " it's okay, okay, everything is alright" . So when I make a mistake, and people from Kumamoto, Kyusyu say よかばい、よかばい, I feel extra warm relief than the standard Japanese だいじょうぶ.

I dont know ?????????????