I guess there is no right and wrong choice. I've 2 friends, both sign-on and left after 1st contract. One took ACCA, joined SME and then big 3. Now he is a partner (>$20k pm) in the big 3. The other took private degree and now he is a junior exec (<$4k pm) in a GLC. Both are in their mid 30s now. So, at the end of the day, it boils down to perseverance and luck. Like your reason for sign-on, they did it to fund their studies.

My advice? Just do it if you don't have any other means to fund your studies.