Congrats! They do sell for a lot but make sure you have one in your museum before you sell it. By only if you want to complete the insect section:0
Are you in the island? Cause they show often there. Especially after 7pm :0
Then that's why you're catching a lot cx
The other bettles like the elephant sell for a lot. Also go fishing for sharks.
One time k actually filled the entire island basket with golden stags... needless to say I are A LOT of bells that nightt