mummacassie, ask your Vet if he will do a deal and desex the pups and be paid for each one when you re-home them. That way, you are not out of pocket and the pups are desexed before they go their new home. This will also help you with vaccinations. Negotiate a price to desex, chip and vaccinate each pup and then re-home them for that price so that you are compensated.
The feeling of satisfaction you will have at then, knowing that they will be safer in the community becuase they are desexed and vaccinated, will be great.