two issues. Diminishing returns and volume. The more you handle it the more you need to sell it for. The most pure copper will sell for is market value (~$3.10 as of today). So what can you do to the copper to get it closest to that value while handling it the least... Strip it, chip it, melt it... Keep in mind the more surface area the more oxidation can occur. Your bucket of copper power could get ruined pretty quick under the wrong conditions. But a copper bar can be easily cleaned and used. Also volume, a bale of wire vs. a few buckets of powder. Figure how that affects your profit as well. Just my thoughts...