Caleurpa may not be the best bet for a money making venture. It's very available and people tend to give it away or throw it away.
A few bucks wisely spent can get you some very cool specimens. Try different varieties of Gracilliara (round and flat, red and green), halymenia, chaetomorpha, etc. These are specimens that people are far more likely to pay money for. And my halymenia is growing quite large.
Someone stop me! Please! But... not just yet...
55 Gal Tropical FW
55 Gal Mixed Reef