The club's current proposal of €48m plus €7m in bonuses is potentially representing close to their final position.
Speaking after Dortmund's 3-2 pre-season defeat to Arsenal, Ricken was asked about the ongoing saga surrounding the 19-year-old.
"I think we really fight for every euro. The example of Karetsas showed that too," he said.
"We first met in April and we've only just recently completed the deal, because it's important to us to work in an economically sensible way."
Borussia Dortmund eventually signed Konstantinos Karetsas from Genk for €32m including bonuses after months of negotiation, despite the Belgian club having demanded as much as €40m at one point during talks.
Ricken explained that Dortmund's approach to spending had been shaped by a broader effort to manage costs sensibly across recent transfer windows.
"Because we've done that in recent years and also made savings here and there, particularly on squad costs, that gives us room to act. It's about making the right decision, both sporting and financial," he said.
The Dortmund sporting director declined to go into further detail on El Mala specifically, stressing that the player remained under contract elsewhere.
"It's still the case that Said is a player of 1. FC Koln. It's simply a matter of respect that we at Borussia Dortmund don't talk about other players," Ricken said. "That unfortunately sometimes means there are supposed news stories out there, and the day before yesterday we were sitting in the office thinking: 'Look what we've supposedly done again.' We just have to put up with that a little."
Should the deal for El Mala ultimately fail to come together, Ricken indicated Dortmund already have alternative plans in place.
"We still have plenty of ideas. The transfer market is only just getting going in a lot of other markets, and in the end we'll see what the best solution is for Borussia Dortmund," he said.
Cologne have so far rejected several Dortmund offers for the teenager, with reports in Germany suggesting the club is holding out for a fee closer to €50m, and have publicly played down suggestions of an imminent departure. Sporting director Thomas Kessler said this weekend he expected El Mala to remain part of Koln's Bundesliga squad this season, though the player's own camp is understood to favour a move to Dortmund should an agreement between the clubs eventually be reached.
Karetsas, meanwhile, has already opened his Dortmund account, scoring on his full debut in the Arsenal defeat.