The only problem with that league is that there are only two rich teams who can keep their players and those two big teams can't buy literally every good player in the league. The others are forced to sell. If there were only two more financially decent teams, then La Liga would have had Kun, Mata, Silva etc.
True, it is a big challenge for them. It really comes to show the wealth of talent that Spain has though, you have players like Mario Suarez today, who would never even dream of getting a sniff to the Spanish NT, but is an extremely strong defensive midfielder. He controlled that midfield like he owned it today, absolute wall. Spanish teams keep losing their best players but manage to find decent enough replacements. Over the years Valencia have lost Silva, Mata and Villa. Now they have Feghouli, Banega, Tino Costa and Soldado, who are not as good as the former, but are very good players in their own right. Same with Atletico losing the likes of Aguero, Simao, and Maxi Rodriquez, and replaced them with Falcao, Adrian Lopez and Arda Turan.
The way TV money is distributed in Spain might be benefiting Barca and Real but it is hurting the rest of the league a lot.