Instead of spending money, you can just do this:
- In any level, position your mesh so the level origin (@ coordinates 0,0,0) is wherever you want your mesh’s pivot to be
- right-click the mesh, select option “Merge Actors” in the context menu
- in the new Merge window that appears, ensure that your mesh is the only (ticked) item in the list at the top (untick any others if accidentally selected)
- Tick option "Pivot Point at Zero"
- Press Button “Merge Actors”, select subdir (e.g., Meshes), provide a new name, press “Save”, exit first window
- Discard your original mesh, and drag the new one into your level; the latter has its pivot where you positioned it (permanently)