Generate a decision tree for evaluating whether to hire for a specific task or complete it solo as a solopreneur.  The decision tree should consider factors such as: project scope (small, medium, large), urgency (immediate, short-term, long-term), budget constraints (tight, moderate, ample), existing skillset (proficient, intermediate, novice), time availability (abundant, moderate, limited), and potential return on investment (ROI) for hiring vs. solo execution.  Each node of the decision tree should lead to a clear recommendation (hire, solo, or further evaluation needed) with a brief justification. The final output should be formatted as a structured decision tree using a text-based representation, with clear branching logic and leaf nodes that offer a conclusive recommendation.  Illustrate the decision-tree with at least three distinct example scenarios: (1) a small, urgent project with a tight budget, (2) a large, long-term project with ample budget and moderate skillset, and (3) a medium-sized project with moderate urgency, a moderate budget, and novice skillset.  The validation criteria for the generated decision tree should be its completeness (all relevant factors considered), clarity (easily understandable recommendations), and its practical applicability for solopreneurs facing hiring decisions.  The decision tree should also consider the opportunity cost of time spent on the task versus the cost of hiring.