I just did quick googling how much reptile food cost in Australia, frozen rabbit is from 23 australian dollars (200-300 gram) to 36 AUD (1kg) so you should be asking more than that to avoid interest from people buying cheap rabbits for their reptiles. As far as I know selling living rabbits for feeding reptiles is illegal but there is always black market so just find out prices on that and make your price higher than that.
I second that babies must be with their mother until 8 weeks at least and get mothers milk. Until 4 weeks you don't spend on them, only feed mother unlimited pellets so she can produce quality milk to feed them, but when they start eating solid food it will add cost to your expenses. If you got 6 babies there, they should eat unlimited high protein food (up to 200 gram per day instead of normal portion 50 gram), nursing mother is also on unlimited pellets so with 7 unlimited rabbits you will have to buy one 2kg bag of food per day, maybe two days since they are mini sized, but still, it's one month's food for one rabbit. They are growing and every day will eat more and more so that will cost you. Hay is cheaper, well depending where you buy hopefully not from petstores, that would be very expensive.
So if you think you can get lots of money selling your babes it's not that easy, be happy if you cover your expenses.
For max price check out your local online advertisements boards, I agree that make it sounding more like rehoming fee rather than price for the rabbits and make it equal for all babies.
When advertising you try selling boys first because it is not that fast it may take time a few weeks to few months if you want them to go to caring homes. Boys will need to be kept separately each individually from about 10-12 weeks when they will start fighting, so keeping girls would be a bit easier they can stay with mother until up to 5 months if needed, then they can also become territorial and will need to be separated, it depends on your rabbits how long.
Breeding rabbits is not as profitable as it can look if you want them to go to loving homes. It's expensive actually, that's why surprise breeders are giving their babies for free rehoming, to avoid extra cost and work, extra expenses on additional cages/housing when you need to separate boys from girls first and then boys keep individually housed.
Free or cheap babies often go to reptiles or dog baits (takers will never tell you that they will send you fake photos of where they will house them and will ask their girlfriend or grandma to collect them for her kids), it is hard to know if there's genuine people or not. Also some people buying females to breed them commercially every month just selling one-two week old babies as frozen reptile food. They usually kept in horrible conditions and fed scraps, they are just working does.
If your price is too high it can take time to sell. If you want to sell responsibly of course it would be best selling already neutered and in bonded pairs, but neutering is expensive and you will need to keep them until 6-8 months at least so in reality you will never get what you spend on babies.
So that is how you set your price, above reptile food price but keep an eye on your local market prices for your maximum, keep in mind that every day will take money from your wallet, be open to negotiations for right people.
Selling in pairs is more economically attractive but remember that selling two 8 week old boys might cause problems for people in just a few weeks since they will need to separate, neuter and rebond them or rehome one boy because two boys can rarely live together they will fight sometimes to death for dominance, you don't want to sell a problem to some nice people right?
Selling babies in pairs is not easy at 8 weeks they are often mis sexed so people buy two sisters and then have a surprise litter a couple months later, you know that. When selling in pairs you should warn about separating and neutering and rebonding if people want to have a pair. People can change their mind when you warn them about future problems so most sellers won't tell you anything, you want two, sure great they are best buddies (at 8 weeks).
In short, you can start advertising when they are 6 weeks stating that they are ready to go in two weeks when fully weaned from their mother.
Price should be higher than reptile food but not max as takes longer to sell, check your local prices and keep on middle.
Incalculated one month food supply often would make your higher price more attractive, anyway you should give changeover food pellets for one week at least and instruct that they should stay on same pellets or if changing do it gradually mixing old pellets with new to avoid upset stomach and more serious health problems.
