Startup cost: $500 - $3k

Setup costs range from $500 to $3,000 depending on the scale and quality of tools you choose for a Custom GPT Builder side hustle. At the minimum end, one would need to budget for domain registration, web hosting, and basic coding tools. On the higher end, additional expenses might include premium AI software subscriptions, professional website design services, and marketing tools. Essential expenses at launch include domain registration, web hosting, and coding tools, while optional expenses could include premium AI software and advanced marketing services. Hidden fees may arise from software upgrades, maintenance, and marketing campaigns. Online feedback suggests that costs can escalate once committed due to the need for better tools or services. To take this side hustle seriously, I would advise a friend to budget between $500 to $3,000 to cover initial setup expenses and ensure a competitive start in the custom GPT builder market.