Per the ING calculator [https://www.ing.com.au/home-loans/calculators/repayments.html], $350k at current rates of 5.42% would mean that you pay $709,100 in all with minimum payments. Taking it out today, you'd pay it off in 2048.
An extra $100 a month means you pay it off 3 years earlier in 2045, and saves you $46,000.
$500 more a month means you pay it off 11 years earlier in 2037, and saves you $149,000.
$1,000 more a month means you pay it off 16 years earlier in 2032, and saves you $208,000.
And so on.
It is unclear to me why anyone would want to take longer to pay off their place, and spend more money on it than they have to. But perhaps you wish to start a charitable foundation to help our banks, since they're struggling so much.