yeah you can a 'better' reward every 10 quests, but reward maybe kinda too underwhelming for tortuga now. Also when your char's level become higher than 55, you'll start receiving sea killing/farming quests, which will make things more annoying and less profit efficient. If you do want to do life quests, I think there're some ppl make a lv55 char especially for life quest and keep the char at that level.