What do you think i should do?

I have paid �25 for a skwl trip to Oakwood ( i neva been ther before ) and just then i found out my head teachers retiring party is on the same day. All my old skwl friends are going and i havent seen them for like a year so i wud love to see them again. My friends who are also going to Oakwood really want me to go there but my old school friends want me to go to this party. Im not sure if my skwl give you the money back and i would not want to waste my mums money as shes a single mum and we are struggling at the moment but i really want to go to this party! I know its a bit of a pathetic question but i need to know what you would do! Thanksss :/