Being 5 years old , I will excuse the misspelling of Qantas

I will assume that your information regarding Marriott to Qantas conversion values are accurate

If you redeem 375k Marriott points, your Qantas FF account should be credited with 105k points

A simple award ticket from Los Angeles to Australia costs 96,000 points one way in business class

I would be thinking that transferring Marriott points to Qantas for an award flight may not be a good option

Can Marriott points be transferred to AA ? If so, then 125k AA points can be used to redeem a business class return flight between USA and Australia/NZ on Qantas ( plus you would avoid a few hundred dollars in fuel fines ) ; alternatively can they be transferred to UA or US since then can redeem on NZ/UA at a similar rate to AA

It looks like you can ( or could ) transfer to US; if you transfer marriott points to US, you would end up with 105k; you can purchase the remaining 20k required for an award ( and US has been having a decent number of promotions where you can purchase miles at half price ). This , I suggest, is going to be a lot better value than getting 105k Qantas points