3x on the button seems like overkill. 2x or 2.5x seem reasonable.

2x has to work 57% of the time.
2.5 has to work 62.5% of the time
3x has to work 67% of the time.

I don't think the number of folds you will get with 3x over 2.5x warrants risking 0.5 more each time. Also you will get 3b bigger and you will have to 4b bluff bigger now as well.

As for the hand, seems like a very easy river b/f. Nobody is assuming you have a straight, people ARE assuming you can have a flush, so you have waay the bottom of your perceived range here.