There are a couple of things related to this question:
1. Budget level box: We show a budget level box for Sections such as "Restaurants" or "Hotels", but NOT for "Sights and Attractions" (because it does not make sense for sights and attractions).
2. The URL you gave is listed as a "Transport Station", but Wat Arun is in fact a "Sight & Attraction", and the description on the page also reads like a description for an attraction.
3. Therefore, I have moved the entry to the "Sights & Attractions" section. It now does not show the budget level any more. New URL is http://www.guidegecko.com/bangkok/rattanakosin-monuments-buildings/wat-arun/p,608170734
I believe this solves the problem.
Now to your original question - is there a guideline for price ranges - what budget levels refer to which price range?
Answer: This would depend on the country and the type of place (e.g., is it a restaurant or a hotel). For Singapore hotels, we use this scheme: http://www.guidegecko.com/singapore/travel-tips/singapore-accomodation-price-ranges/p,608168761
Of course, this may need to be adapted to other countries.
Hope that helps!