You may like it or not but in Thailand it is common practice that foreigners and tourists pay much higher entrance fees than Thai people. It is not really fair but there is no way around it.
BUT you might feel better when you realize that Western wages are much much higher and so tourist can in fact easily afford it.
Last week we went to the Lumpini boxing stadium and the entrance charge for was 30 Euro. Thai-price 10Euro.
We went to have a beer instead. Enjoy
Here is an example of pricing for the Crocodile farm:
Bangkok Market
Popular markets and a lot more.
