I have made about 85k in one month only from melons and making a 10x10x10 protected melon farm only takes an hour and less investing around at 2,1k (1.500 for a small protection) and the rest for the tools lets say a diamond pickaxe. I do believe that melon prices are high but with just one farm its hard to make money. Now i have 3 farms and with an efficency II pickaxe i am making about 5x64 blocks of melons, wich is 4800$, in about every 45 minutes (giving time to melons to regenerate wich they do very fast). To get to the point , indeed are the melon prices high but for starters its hard to get and craft 9x64 melon slices in blocks.