Depending on the size of the objects, one could use Workers KV ($5 per 1M writes, $5 per 10M reads, 25M size limit) as a pseudo-R2 store [0] via Workers Unbound (~$1 per 6M requests), especially with the recent optimizations bringing the bills (of Workers Unbound proxying KV) down by 70% [1]
[0] https://news.ycombinator.com/item?id=28747798
[1] https://blog.cloudflare.com/workers-optimization-reduces-you...