Basic phone
Well, the MT8841 seems to be obsolete in my web searches. Another way to do this is to use a PC, personal computer. While it seems like overkill, you can get working PCs for less than $20. Then all you need is a cheap modem to access the phone line and a some software. A quick web search revealed several shareware and freeware programs that can read the caller id. In addition to that program, all you need is a script to compare against the two phone numbers.
If you only need one of these and space exists for the PC, then it could be easily assembled from surplus PC parts for less than $100. If you have to buy the caller ID chip, the microcontroller, make a PCB etc your single item costs add up quickly. Just a thought.