The Esrog business definitely seems to be 'somewhat imprecise' and prices may be inflated based on the mood of the seller and the face / suit / watch of the buyer, however there is a certain element of hiddur mitzvah to pay the requested price inorder to be mekayem a mitzvah even if it exceeds the true market value for whatever reason. If the price is excessive there is certainly no chiyuv to be 'mevazbez' but the Zohar (2:128a) tells that one who wants to have a shaychus to kedusha:
. הַהוּא עוֹבְדָא דְּבָעֵי לְאִשְׁתַּדְּלָא בֵּיהּ, בָּעֵי לְמִקְנֵי "לֵיהּ בַּאֲגָר שְׁלִים, בְּכָל מַה דְּיִבְעוּן מִנֵּיהּ, בֵּין זְעֵיר בֵּין רַב"
"The action (mitzvah) that he wants to try and perform he needs to buy it for full price, whatever they ask of him whether a small amount or a large amount" "..... For ruach hatumah is attained always and for free ... And is sold at no cost ..... The ruach of kedusha is not so, rather a full cost and with great personal investment"
The Gemoro (sukkah 41b) relates an example that is quite apropos, that Rabban Gamliel bought Arba minnim for 1000 zuz, and the Gemoro clarifies:
למה לי למימר שלקחו באלף זוז להודיעך כמה מצות חביבות עליהן
Why the need to inform us that he bought it for 1000 zuz? To let us know how dear mitzvos were to them.
Not to say that we all need to sell out cars and houses and spend $50K on esrogim, BUT, I think it does give a little context to the issue at hand.
PS a huge shout out to chase bank for assisting yidden to be more readily able to be mehader b'mitzvos!!
(UR@1.8 > new mehudardikkeh tefillin, mehudardikkeh Abraham minnim, vchu')