The more I read about the TA824 the more I agree. I looked at photos of the doorphone cards for both the TA624 and TA824 and they are different but I can pick up a brand new one for under 100 once I get a decent control unit. I noticed they got smart on the 824 and instead of a fixed ROM chip you can update firmware like you would a printer or router, via USB. Also checking I see my phones and TVS50 will work with the 824 pretty much the same as with the 624 and I can use the same doorphones just have to get the different doorphone card. I shouldn't be out a great deal in the end once I sell the old 624 that has a CID card, 6co and 16 stations and doorphone card. Won't break even but won't be out the full amount either, and I'll have much better CID than the 624's system. I noticed the TA824 isn't that old since the manuals are copyrighted 2005 and 2007.

The price you have to pay when you need more than one CO line and other specific features. Appreciate the help so far, hopefully with the software setup it won't be as painstaking getting the TA824 setup when I get my hands on one.