How to develop an application for your online store and is it really worth all the investment? This is a big dilemma for me.

Contact the developers or development company first for a consultation to find out the cost, and then make a decision.

Now there are no problems at all with setting up, developing, creating something from scratch, or adapting ready-made solutions. In any case, I recommend Amasty specialists and their shopify app development services to you. It seems to me that working with these experienced specialists you can count on excellent results.