So the easiest way is to create a custom tickets.php template. If you are unsure about how to do this, please see:
In essence though you would copy tickets.php from:
wp-content/plugins/wootickets/views/tickets.php
And place the copy in your theme’s events sub-directory (which you would need to create if it does not already exist):
wp-content/themes/{YOUR-THEME}/events/tickets.php
Then, look for the start of the ticket loop. It will be a line like this one:
foreach ( $tickets as $ticket ) {
Just above that you could insert this snippet or, if that doesn’t work, it could be you need to use an older form of the same code. That should cause the tickets to display in price order, lowest to highest.
I hope that helps but let me know if not/if you need clarification.