Depends what it means to you
Whether the £140 is worth it depends entirely on what a sponsorship would mean to you.
If flying for a career means the whole world to you (as it does to most people on the forum), then yes, I suppose it is worth it. If an ATPL is your goal and you pay £140 for tests, but don't get the sponsorship, then when it comes to Plan B....self funding, the £140 may seem small in comparison. i.e 1.5 hours flying?
I appreciate what it is like being at Uni and skint (did 5 years myself). If you were to succeed at stage 2, how would you feel about paying £400 for the class1, then signing your name to a £60,000 loan?
So really no-one else can answer that question for you, it depends on your (current) position and what value you place on an ATPL sponsorship.