You must learn mesh to make a profit in SL now. The good news is prim building translates into mesh. It's the same thing with vastly more capabilities once you're proficient. Took me 3 months for basic proficiency by watching YouTube tutorials nonstop. It can start as a hobby but grow into lucrative income depending on your skill and dedication.
Edit/Add: You can make a huge profit selling mesh body appliers too using Photoshop skills without any mesh skills.