Sorry I don't know the show, but I have done a lot of really low budget high school shows.
First of all start with what you have:
-Do you have flats in
stock that can be re-painted?
-Do you have any platforms, stairs,
etc?
-Do you own anything that could be part of "the set"? Choir risers, drum
riser platform, Heck I did a production of Mid Summer that was in a "Pillow Pit".. no set just pillows.
Second who are your friends and what do they have available?
-Assuming you are in a high school, are there other schools near who will loan you things?
-What about colleges and universities?
-Are there community and semi-pro theaters in the area? Typically all but the biggest theaters will loan out furniture and other stuff to you for a "Pull fee". A pull fee is just a
flat rate to
cover the cost of them having an employee deal with you. Around here Pull fees run $25-$50 depending on how much stuff you borrow and how much of their time you take.
Once you have an idea of what you can get a hold of cheap you begin your design process. Avoid building as much as possible as you will burn a huge amount of cash buying lumber. Typically the cheapest sets are ones that have a variety of levels which can be symbolic of a variety of different elements in the story. Add some sort of generic background that can work for the whole show and you've got a cheap set (or just do it in front of a colored
cyc or black curtain).
P.S. All those community theater and college theater connections are awesome for costumes too! With the right connections you can costume an entire show beautifully for $25-$100.