Dati nung nagpunta kami, i guess kung transpo (balikan) and lodging (overnight) ang usapan, you would need something around 500 siguro. Yung food naman and others, shempre kanya kanya na yun since dati kanya kanyang dala ng snacks saka food for meals (potluck naman)...
I guess bukod sa 500, dala na rin ng pocket money just in case may emergency money needed for some expense... pero the general rule is the more na maraming sumama, the cheaper the lodging gets