Craigslist does not permit animals to be sold through their site.
If you're SELLING animals, then the flaggers are doing the RIGHT THING. You're in the wrong, not them.
A rehoming fee is a small fee to ensure that the animal goes to a home where a person can care for it. A rehoming fee for a green anole shouldn't be significantly different than one for a high end leopard gecko, because the animals need a similar level of care, and the VALUE of the animal is IRRELEVANT---if you're actually trying to just find a home for it.
If the value of the animal matters, then you aren't adopting an animal out, you are SELLING it. If the cage costs money, then mention that the cage is for sale, and optional--it's legal to sell cages on Craigslist.
So, good for the flaggers. They're just helping to enforce Craigslist's TOS. If you don't like the rules on Craigslist, then don't use Craigslist. Breaking their rules to post animals for sale makes you and your business look bad. It is dishonest. Dishonesty in one area implies a willingness to dishonesty in other areas.
If you want Craigslist to change their policy, then you should work on petitioning them to do so (though i wouldn't hold my breath).
In the meantime, if you have animals to sell, Kijiji/Ebay Classifieds permits animals for sale, as do MANY other classifieds sites.