im a surfer but i need a new shortboard - preferably cheap!

I need a bit of help...
Im a surfer, and ive been surfing on and off for the last year, surfing on rented or friends boards. I found that im good at surfing and would like to get seriious. But the only shortboards i can find that are the size i want (5'10 to 6'4) and really expensive and my parents arent will to spend that much. I need some help.
Any suggestions for a lost surfer in the boston area?????
Im a surfer, and ive been surfing on and off for the last year, surfing on rented or friends boards. I found that im good at surfing and would like to get seriious. But the only shortboards i can find that are the size i want (5'10 to 6'4) and really expensive and my parents arent will to spend that much. I need some help.
Any suggestions for a lost surfer in the boston area?????