In very cost sensitive applications where you want 'managed' and 'cheap' like security cameras for an ordinary house, the best non hack solution I've found is to have something like a basic managed non-PoE switch, and then hang a dumb switch downstream of it for the sole purpose of aggregating something like IP cameras.

For example some of the cheaper unmanaged 8-port 802.3af/at switches with enough power budget for 7 cameras. Average traffic from a single camera isn't a lot, easily fitting in a single 1000BaseT link to the managed switch. Put the whole dumb switch in the camera vlan.