Thanksgiving for a Miracle
The Shulchan Arukh states that we should make a blessing after any Divine salvation (OC 219). However, we also find that it is proper after such salvation to make some kind of practical contribution to the community afterwards. We learn this from Yaakov Avinu; when he was saved from Esav and arrived at the outskirts of Shechem "whole in his body, whole in his possessions, and whole in his Torah", he decided to "grace" the face of the city; the gemara tells us that this was done with practical steps to improve the inhabitants: according to one opinion he established a system of coinage; alternatively, he established a marketplace or a bathhouse (Shabbat 33b).
The gemara states that Rebbe Shimon concluded from this that when he was miraculously saved from the Romans by hiding in a cave, he also should engage in some practical step to helping the inhabitants of his town.
The Yerushalmi goes farther and states that Rebbe Shimon said, "We are obliged to make an improvement, as our fathers did" (Yerushalmi Shviit 9a).
What is the special significance of the three examples brought in the story - coinage, markets, and bathhouses? The Maharal gives a fascinating answer, pointing out an essential difference in the type of improvement.
The Maharal points out that the benefit of coinage is completely conventional. A particular substance or symbol is accepted by one person as money only because he knows that it will be accepted by others as money. (In our day, money has no inherent value at all, yet it is not any less useful.) This improvement is basically in the social organization of the people.
Marketplaces have both a conventional as well as an inherent benefit. The very fact that people trade with each other is an inherent benefit, yet marketplaces typically have extensive rules (the Maharal gives the example of market days) which advance commerce if everyone holds by them; this is the conventional dimension.
Bathhouses, finally, provide a completely inherent benefit. Any individual can benefit from one, whatever his relationship is with others (Chidushei Aggadot).
Extending the Maharal's idea, perhaps we can discern a significance in the order mentioned in the story. Since coinage is mentioned first, the message seems to be that the most important "improvements" of all are not physical improvements per se, but rather improvements in social organization, which serve as a foundation for all other types of advancement.