PeerJ (https://peerj.com/about/how-it-works/) has a limited cost APC, or none from some institutions, and a lifetime membership for a one-off fee that allows publication of one paper a year (https://peerj.com/pricing/#apc-membership-pricing). It also operates a free to submit pre-print server that can act as a jump-off point for a full publication in the PeerJ journal or is acceptable to many other journals.