Money in Luxor is straightforward if you know a few things in advance. The Egyptian pound (EGP) is the local currency. You will need cash for small purchases — vendors, tips, entrance to some minor sites — and most restaurants outside the hotels. ATMs are widely available in Luxor city and in the Karnak area.
Tipping is a real part of the economy here, not an optional gesture. The people who help you — drivers, site guards who illuminate a painted detail, the boat operator who takes you across the Nile — depend on it. I do not tell you how much to give anyone; that is between you and them. What I will say is that generosity is remembered, and this is a small city.
USD and EUR are widely accepted at larger hotels and some tour operators, but the exchange rate at the hotel desk is usually worse than at a bank or currency exchange office. I can direct you to reliable exchange offices if needed.
Photography permits are a recurring cost. Some sites charge separately for camera use; others include it in the ticket. I handle site entry logistics for my clients — entrance fees and permit costs are factored into what I quote you, not added as surprises on the day.