Advice on a purchase

Hi. My son is 14 years old and plays an upright bass. We are currently renting his bass and up until September 2008 he was using the school bass. He has been playing since 5th grade he is now a freshmen and has made All state orchestra twice in the last 2 years and plays with the local orchestra. He enjoys paying and practices without being told or encouraged.
I have been searching the internet for basses that fit our budget( with 2 in college our budget is pretty small). Ebay has several in our price range but I have little or no working knowledge about the subject. I have read quite a few reviews on the subject and it is now clear as mud. The DeVilli 4/4 or 3/4 look good to me but I need to be sure before I invest the part of our income tax return in this purchase. I would appreciate any information you could give me. Paying $60 a month for an upright seems a little expensive to me even for Delaware.
Thank you for your time and consideration.