It is not so much about needing the money from kitten sales to continue to breed but more about not having adequate money and room to keep kittens which are not re-homed, even with only one queen there is the possibility of having up to 8 kittens at any time and no guarantee that homes will be available. Breeding and raising kittens cost a lot with vaccinations (£50 per kitten), neutering (£40-50 per kitten), food, food for the pregnant and then nursing queen, the initial health tests for the queen (£30 PK-Def test, £285 per year HCM screen for us per cat, £50 snap Felv/FIV test prior to every stud visit), the stud fee which is often upwards of £500. If every kitten you breed was not sold could you afford to either keep all of them with enough space for them to live happily in your home or take the loss and re-home them all for free?
We had to give kittens away for free because we wanted all of our cats to live in the home with us and not have to be housed outside and having entire cats, older kittens who had not sold and also younger kittens still with their mother was not viable. The younger kittens were born after the date the older kittens should have left for their new homes but unfortunately there was no interest until they were advertised as free
If there is no market for kittens in the area you live then unless you can realistically keep every kitten you produce then continuing to breed is irresponsible, the options are moving to somewhere with more demand or not breeding at least until the market in your area improves which is the course we have taken in retiring our cats and no longer breeding. Honestly I feel that the market is saturated with Bengals and Bengal crosses these days and I would not recommend anyone beginning to breed at the moment. As you are still only learning about the breed my advice would be to continue learning and researching for a good few years and then re-assessing the market to see if the breed has recovered before committing to a breeding program.