mrsurrey,
i too am a university finalist with fours years student loans behind me (as my name would suggest) however i would suggest that £140 is well worth paying for an opportunity like this. At the end of the day its a small fee in comparison to the 60,000 you will probably have to borrow if successful! Frankly I will be coughing up the money if i have to beg borrow or steal!!
Good luck.
I dont think the dates you are available determines the promptness of reply. I applied on the wednesday after it went live and said i would be available from august. Received my stage 2 invitation on monday.