Canada-based gold and silver producer GoGold Resources (TSX:GGD) definitely had plenty of reasons to be happy today. The company released the initial preliminary economic assessment (PEA) for its Santa Gertrudis project in Mexico, and the numbers are impressive, to say the least. Highlights from the report include a net present value of US$150 million and a post-tax internal rate of return (IRR) of 58 percent with a payback period of just 1.7 years. Initial capital expenditures are set at $32 million for the project, including a 20-percent contingency, while after-tax net cash flow will come to $232 million. Contributing to that low capex is the substantial amount of existing infrastructure at Santa Gertrudis. The past-producing mine stopped operating in 2000, but features "numerous pits already stripped with haul roads," making it almost "ready to start mining." GoGold intends to develop the project as a 7,500-tonne-per-day heap leaching facility fed by several open pits, with the mine expected to produce an average of 56,000 ounces of gold per year over a projected 12-year mine life. Additionally, the mine is anticipated to have a low, all-in sustaining cash cost of just $699 per ounce of gold. GoGold's president and CEO, Terry Coughlan, commented on the results in today's release, stating "[w]e are extremely pleased with the results of the initial PEA study for Santa Gertrudis. The large increase in gold ounces along with the robust economic opportunity to develop our second low cost producing mine in Mexico, substantiates the reasons why the company was so eager to secure this gold project for our shareholders." How low can you go? Even more interesting for investors to note is the base-case gold price that the company used to get such impressive numbers for its PEA. GoGold took it down to $1,250 per ounce, giving investors plenty of confidence in terms of the project's ability to weather varying market conditions.