Start with ChatGPT's free plan, or Gemini's free plan, when you want a draft and a price you can read before you open an account. ChatGPT's pricing page does not describe a live flight or hotel search. Gemini's app page says the assistant can make mistakes and did not show a booking screen. Both are drafts you check against maps and the provider's own site.
Open Gemini when the published ladder matters and you already live in a Google account. The United States page prices Plus at $4.99 per month and Pro at $19.99 per month. Ultra starts at $99.99 per month, with a $199.99 per month option for higher limits. The page says the country is the United States, so confirm the figure where you live.
Open Mindtrip when you want a product built for the trip, with listings rather than a blank chat, and you can accept an unknown subscription price. The October 19 homepage says you can book on Mindtrip or let the assistant handle details, and it mentions price drops and flight changes. October 20 returned a browser check. Do not pay until that page loads and shows the current cost.
They answer different questions. ChatGPT and Gemini are priced assistants you can use for a first draft. Mindtrip is the one whose last loaded page is about booking the trip. If you need the plan without a subscription and you want a travel-only tool, use a free planner from the directory and book the expensive parts yourself.