Bay City is pretty unique (and the land has double prim allowances). There are a few other communities (loosely) not too far from Bay City, but not on the same level of roads, parks, etc., as Bay City, in my opinion.
While Bay City land is very expensive to buy, there are several rental companies with very reasonable rental rates for land there. One is Robin Ivory who occassionally has a lot or two for rent, the other is TowerRental.
If you just want roadside land, the best way to find it is to look for land for sale along the roads on the SL map of the mainland continents. All the m