You should be able to find a bike co-op somewhere near you. You may be able to trade out your crankset for a compact double. Used or recycled parts and it would not cost much. Same with a derailleur and rear cassette. However a chain, cassette, and derailleur is going to cost a fair amount plus depending on the condition of your chain now and current chainrings you may also need new chainrings anyway. New chainrings can get spendy as well. However if you deal witha shop that buys direct from Shimano the prices can be quite competitive. 39-25 is a fairly tall gear but if it is all you have you may be ok if it is just a steady climb. You might be able to
#cross-train as @
IBOHUNT calls it the steep parts. (get off and walk)