The billion dollar company said committed expenditure at Honeymoon in South Australia totaled 77% of projected spend, with capex previously put at around A$110 million.
At the end of March, Boss had A$103 million cash.
The uranium price of US$56 per pound means a stockpile Boss owns is worth about $70 million.
Boss aims to produce an average of about two million pounds per annum for 11 years at an "all in cost" of about US$32/lb.
Boss said discussions with potential offtake customers were continuing.
Investors have been increasingly backing the story, with the stock up 70-80% over the past 12 months.
Shares in Boss were trading at A$3.09 this week, capitalising the company at nearly $1.1 billion.
