Are you counting domain renewal cost plus hosting cost? NameCheap IO renew is $33 only, so there could be a cheaper hosting option if that is the case.
My guess is your ads are not supporting your yearly cost, correct? Would you consider a PayPal Donate or Patreon, your users might pitch in to keep it going, seriously, if you had only 60 users who would support you with one dollar, that would cover it.
Also you can float your IO renewal by 90 days, if you were just keeping the domain, but your site will not resolve in the meantime