Access to accurate, granular, and up-to-date poverty data is essential for humanitarian organizations to identify vulnerable areas for poverty alleviation efforts. Recent works have shown success in combining computer vision and satellite imagery for poverty estimation; however, the cost of acquiring high-resolution images coupled with black-box models can be a barrier to adoption for many development organizations. In this study, we present a cost-efficient and explainable approach to poverty estimation using machine learning and readily accessible data sources including social media data, low-resolution satellite images, and volunteered geographic information. Using our method, we achieve an R-squared of 0.66 for wealth estimation in the Philippines, an improvement over previous benchmarks. Finally, we use feature importance analysis to identify the highest contributing features both globally and locally to help decision-makers gain deeper insights into poverty.