Jair the Gileadite judged after Tola. His legacy is that of wealth. For him to be able to support a household of 30 sons. Beyond that they each rode a donkey. Donkeys, as a beast of burden, were used to carry stuff and rarely people. In all likelihood that means each son had enough animals that they could use one simply for themselves, meaning their feet rarely touched the ground. That’s a high-status symbol even today.
There are a few reasons to include this story of an extra wealthy man becoming a judge. Most stem from the change in location. The first thing this accomplishes is to prepare us for the next judge, Jephthah. Gilead is an interesting land which is split between Manasseh, Gad, and Reuben. It was once held by the Kings Og and Sihon. Gilead, the person, is believed to be the grandson of Manasseh, making Jair and subsequently Jephthah of the half-tribe of Manasseh.
The second interesting thing about the change in location is that it reminds us that despite the small locus of the last few judges the problems felt there are representative of the whole line of Jacob. This inclusion of the area of Gilead is especially important because they are on the East side of the Jordan river and problems and even cultures are often delineated by something geographical like a river.
The final interesting thing to me about the change of location is that it lends support to the idea that God is active beyond just the limited focus of what is actually written in the Bible. What I mean by this is that God is moving not just in the Jewish culture but others as well. While the Jewish culture is the one to record their relationship with God that does not mean that He has no relationship with other peoples. The best example of this is Melchizedek who is not connected to the Hebrew lineage in any way. Melchizedek is a priest of God who meets Abraham, and his priestly order is fulfilled in Jesus, something that is not predicted in the Hebrew scriptures. To me, the take away is that sometimes we need to broaden our scope of what God is doing in the world. God is not limited, and for me to assume He is only in my area or my people or situation is very arrogant.