The raid to capture Elian and take him back to Cuba took 30 agents, let's say they spent 1/2 a day doing that. 15 agents per day times 800,000 DACA is 32,000 man years or about $5 billion. That doesn't account for the extra police used to disperse the hundreds of Cuban protestors.
We could deal with the 11,000,000 (or 2 or 3 times that) by cracking down on employers and taking in money in fines. Instead you would spend billions rounding people up. Not just criminals or unregistered illegals, but DACA who have registered and are therefore much less of a threat. Not cost effective to say the least.
I repeatedly plead for e-Verify to be implemented for all current and future work. It would solve most of the problem by removing job opportunities. That should go with the wall.