High-tech and non-high-tech entrepreneurial startups (ESUs) progress through distinct lifecycle stages, each with unique characteristics, requirements, and costs. These stages begin with Ideation in the Development phase, followed by Startup, Survival, Growth, and Maturity. The Development and Startup stages are early phases, Survival is the pivotal mid-stage, while Growth and Maturity represent the late stages. These stages resemble levels in a video game, where successfully completing one unlocks a new stage with larger, costlier challenges. Each stage has its own unique characteristics, processes, and cost assumptions. There are no guarantees of success or progression from one stage to the next. However, what remains certain throughout all stages is the costs. As ventures scale, pivot, and grow, cost assumptions shift to dramatically higher values, along with the associated risks. This chapter delves into the early Development and Startup stages, which require research and development, effectual experimentation, and comprehensive analysis of the problems ESUs aim to solve. This includes customer, market, demand, competition, and impact assessments. These early stages involve lower cost investments, the highest risk of failure, minimal predictability, and higher ROI expectations. They are typically net cash burn phases with sunk cost benefits. The strategic focus at this stage is on defining the problem and its impact, achieving problem-solution fit using enabling technologies, and establishing proof of concept with early customer acquisition pilots. In these early-stage ventures, people and technology are often seen as one and the same. Here, costs primarily serve as enablers of value creation. This chapter also defines the nature of costs, outlines their characteristics, and provides step-by-step guidelines on what to do (and what to avoid) during these crucial early stages.