Plan on $2800-$5000/acre for startup. Depends on if you can get by without drip irrigation, the low figure is for the trellis & plants. That small an operation means hand-picking, which is a bit labor intensive at 1-2,000 pounds an acre. You'll also need a drying building, which you'll only use a couple weeks a year. Lots of natural gas or propane.
Hop yards run 500-1500 acres and use automated pickers, so finding info for a small operation will be tough.
If you read German, most hop farms over there are in the 4-5 hectares. They tend to specialize in flavor/aroma hops and that might be your best bet.