I am in two different NL only leagues and both leagues are looking for a couple of new owners. One of the leagues may be folding, but I know one is not. The one that I know for certain has at least 2 openings. It is a pay league ($100 entry fee), but teams taking over a new team get in at half price ($50). You also pay $1 per add drop transaction (trades are free). Fees are collected at the END of the season, but the $50 would be paid prior to opening day. Whatever the total collected for the transaction fees ends up being, gets divided among the top 4 teams. It is a keeper league and it is a live auction draft (where you have $260 to spend). 3 of the owners are in Atlanta, GA (where I am from), and the rest are from Chicago and Milwaukee. It is a good league and I've been a part of it for over 10 years, so it is well established with reputable owners.
The other league I am in that may be folding, needs 5 owners (10 owner league). One owner is moving to Australia and the others decided to "retire" but if can find enough owners to take over the teams, we would love to keep the league going too. It was established in 2001. If you have any interest, or know of anyone else that might, please let me know