How do we get that same money in Spain?
Not much can really be done now. Time to get money was in a decade where La Liga had Messi and CR (alongside other great/marketable players) in their prime years going against each other. If EPL would have only one of them let alone both their TV contracts would be 3-4 times bigger than they are right now.
Instead of using Messi and CR to bring money to the league Tebas managed to get La Liga in a situation where top 6 teams have to sell their players to teams that are fighting against relegation in EPL. Newly promoted Nottingham Forest spend like 170m to buy entire new team last summer. Most promoted teams in La Liga can only sign players on free contracts and loans and can't even dream about spending that kind of money in 15-20 years. Even if they would somehow sell their best players for big money strict Tebas rules would only allow them to invest part of that money into new players.
Obligatory release clauses (which are based on 40 or something years old law) are also one of the reasons for downfall of Spanish football. Most smaller clubs have lost their key players or talented youngsters for basically nothing.
Money spent during the January transfer window:
Premier League: ?353m
Bundesliga: ?34m
La Liga: ?23m
Serie A: ?9m
Ligue 1: ?8m
Yikes
Chelsea alone spend 100m more than other top 4 leagues combined in January.