How far one should travel for an Esrog

How far must one travel to perform a mitzvah? For example If someone doesn't have an esrog, how far must he travel to be able to perform the mitzvah?

Thank you for your question.

Hagaon Harav Amrom Fried shelita says that the question you asked is a dispute between the chayye Adam and the Chinuch.

The Chinuch in mitzvah 5 seif 13 writes that a person has to leave his house and town, and travel to the end of the world inorder to fulfil a mitsvah. And although we may find  a Gemarrah in tractate Pesachim page 3 that says that rabbi Yehuda Ben Besera who lived in Bavel did not come to the beis Hamikdash for aliya la'regel, the reason was not that it was too far, but rather since he was too old and frail or he didn't own any land in Erets Yisrael.

However the Chayeh Adam klall 68 hilchot mitsvot seif 19 nishmat Adam seif 3 writes, that a person is not commanded to leave his house and city for yom tov inorder to acquire an etrog, since there is a mitzvah of being with your family on you tov. We also find in the Talmud Tractate Rosh Hashana, that there where cities in Erets Yisrael who didn't have a shofar on Rosh hashana and some did have, so how could that be? since the people who didn't have shofar should of travelled before Rosh Hashana to the place who had a shofar.

Although the Nishmat Adam writes that this subject stills needs to be clarified, le'halaca a person has to do all he can to aquire an estrog, but he doesn't have to leave his house or  town for Yom Tov inorder to have an etrog.

Whing you all the best.

Sefermitsvat chinuch mitsvah 5 seif 13

Nishmat Adam vol 1 klall 67  seif 19 ot 3