Change the price of all products

You set a filter so that the mass action only affect the products with a price of 50.
So you probably don't want any filter and only an action with a price of 50 set so that it updates the value of all the products.

Then you need to keep the filter on 50 and in your action select INT and enter 114.
Also, add a second filter on "limit" and make sure that you increase the limit as otherwise, it will only apply to the first 500 products costing 50.
Once you're set, you can click on "process" in order to run the mass action and change the price.

This will only do it for 500 products. Do you have more products with that 50 price ?
In that case, you should either rerun it several times or increase the limit.

I'm not just why it wouldn't work with the mass action, but it's indeed quite easy to do with a mysql query.
Simply use such query:

UPDATE jos_hikashop_price SET price_value=114 WHERE price_value=50;