While DMR and P25 are both digital radio standards, they are different digital radio standards. They are not compatible with each other. A DMR radio can't talk to a P25 radio directly in those digital formats. NXDN, or NEXEDGE, is yet a 3rd different digital radio standard.
A DMR radio like a Hytera supports only the DMR digital format, and does not work with P25 systems. Any radio listed as one that supports the DMR standard can decode DMR signals.
Most older scanners that support "digital" radio only decode P25 digital radio systems. Some newer digital scanners support P25, DMR and/or NXDN digital standards. The Whistler TRX-1 and 2 decode all three (P25, DMR and NXDN). The newer Uniden models (SDS-100 and 200, maybe some others) support P25 out of the box and can have DMR and/or NXDN support added at an additional cost.
Unfortunately, because of the forward "progress" of radio technology, as is true with most any technology, the complexity of the radio systems used by our Public Safety agencies has increased notably. So, too, have the consumer-grade radios we use to listen in. And with that increased complexity comes increased cost. Any hobbyist listening to P25 radio systems has invested in a radio capable of decoding P25 systems, and the "new" cost of those radios has always been $300 upwards to $600+.
Obviously, you can find some lower cost radios on the used market, and with that comes risk of buying a used radio. Whistler sells remanufactured versions of their radios (they call them "Scratch and Dent" radios) that are more reasonably priced. It seems that many people have had success with these and found them to be in like-new condition. The remanfactured WS-1040 can be found for less than $200 and it includes some amount of warranty, I believe.
You are unlikely to find a P25-compatible scanner in good working order for less than $150. And you still have the uncertainty of how well that radio may handle the simulcast issues that are prevalent with scanners monitoring that type of system, which is what is in use in Greenville County.
The Broadcastify feeds are provided by volunteer hobbyists, so only that person providing the GCSO feed knows the status of the feed. That provider may be dealing with this same issue, how to afford to dedicate a P25 capable scanner for the task or providing the feed.