MMS is now native to Crestron and the integration is seemless. Too little info to give you a really informed opinion. How many CT-1000? Do they have to be replaced?

My go to design is remotes for TV locations and iPads. Drops cost quite a bit. If we are only about budget then TSW-550 is not really expensive. It also depends on the GUI. My lighting GUI is very labor intensive, though much easier in Crestron then say, Lutron. Having just finished a rather large job, 34 touch panels ( 12 iPads, 6 TSR-302, 5 TSW-1252 11 TSW-752 ) the local C4 rep insinuated it could have done the same job. But I doubt it in part because of the level of cusomization involved.

I'm guessing yours is a standard installation. No centralized HDMI, no integration of CCTV with both mjpg and H264, no security, no SIP integration, no HVAC with systems like Mitsubish where the client wants it as secondary heat but it's only designed to be primary. No custom drivers to be written, you not caring about serial control of display over IR.

If you don't care about a custom UI I'm wagering either system would work for you. Cost: I'm wagering a Crestron system would come in 20% of the C4. MC3, iPad, 550 and existing DA system might even come in at lower price than C4, allowing you to add in MMS and get the streaming audio sources you're looking to obtain. I'm betting that leveraging the existing Crestron DA and lighting, your Crestron system would come in at 12-15K and I'm thinking it might be closer to 12k, including programming. But I'd need more info to be certain about price. What I do know is that few configuration systems allow for the sort of customization Crestron does. Since most jobs do not require great deal of customization I'm betting the programming will not be as expensive assuming your dealer can program in-house

Alan