How do do you decide if this company is worth buying stocks in?

I am asked by my professor to show him in numbers if this company is worth investing in? how do I calculate if it is worth buying stocks in this company for my clients! its a mining company!

Canyon Resources Simulation

Construction Starts in Year 2008
Years in Cash Flow 12
Capital Costs $250,000,000
Total Output (Oz) 4,900,000
Cash Operating Costs (Oz) $200
Gold Price $380
Debt Rate (%) 50.00%
Interest Rate 7.50%
Term (Yrs.) 8
Loan PMT $21,340,878
Inflation Rate 2.50%

State/Local Taxes (Oz) $17.00
Royalty Rate (%) 5.00%
Federal Tax Rate (%) 34.00%
Depletion Allowance 50.00%
After Tax Cost of Capital 17.50%
Pre-Tax Cost of Capital 26.52%

Net Present Value $14,481,692
Internal Rate of Return 20.41%
Pre-Tax Return 30.93%
Appraised Value $389,481,692

Revenue
2009 $155,166,667
2010 $155,166,667
2011 $155,166,667
2012 $155,166,667
2013 $155,166,667
2014 $155,166,667
2015 $155,166,667
2016 $155,166,667
2017 $155,166,667
2018 $155,166,667
2019 $155,166,667
2020 $155,166,667

Expenses
$81,666,667
$83,708,333
$85,801,042
$87,946,068
$90,144,719
$92,398,337
$94,708,296
$97,076,003
$99,502,903
$101,990,476
$104,540,238
$107,153,744

S&L Taxes
$6,941,667
$6,941,667
$6,941,667
$6,941,667
$6,941,667
$6,941,667
$6,941,667
$6,941,667
$6,941,667
$6,941,667
$6,941,667
$6,941,667

Royalty
$7,758,333
$7,758,333
$7,758,333
$7,758,333
$7,758,333
$7,758,333
$7,758,333
$7,758,333
$7,758,333
$7,758,333
$7,758,333
$7,758,333

Interest
$9,375,000
$8,477,559
$7,512,810
$6,475,705
$5,360,817
$4,162,313
$2,873,920
$1,488,898

Prin.
$11,965,878
$12,863,319
$13,828,068
$14,865,173
$15,980,061
$17,178,565
$18,466,958
$19,851,979

Cheating stunts your learning. It may be alot easier, but you are handicapping yourself.
Let me ask this, What do you plan on doing when faced this question in your career? Rely on yahoo answers in investing your clients life-savings?