How much money you make depends on your business model, you could have 1,000 visitors per year, that you sell high value services and net $1,000, or you could have 300,000 visitors per year that you just advertise to and end up making $100.
What cash flow translates into a present value of $10,000... that you can calculate. I would use a "perpetual annuity" formula (look it up online). You would have to start making $500 the first year, with a growth of 5% per year, and a risk/discount rate of 10% (equivalent interest you might pay for this money). That would translate into your $10K initial investment.
From my own personal experience, think of a reasonable number that you think your site will produce, then divide by 100 for the first year. Don't get disencouraged, maybe the second year it will become 1/10 of what you expect.
Maybe try to hack some prototype yourself instead of contracting it. Launch it, and see if you catch any attention... if you do, then have those $10K on hand to contract the development.