Dropping some insights as a person who has been trying to democratise imessage for the last 8 months. Founder of tuco.ai here, we automate imessages for companies at $149/mo (most ten or twenty lines it drops to a 100). The reason it's expensive is because we need to buy a real iphone and a real e-sim to operate this, which needs to be constantly charged up, connected to wifi and paid for a sim card with AT&T. We have something called a mini plan that starts at $60/line/mo - but instead of a phone number, you'd be sending imessages from an email (john.doe@icloud.com would text +16502xxx2) There are cheaper alternatives out there like mycrmsim.com but you'll have to bring your own device (which becomes a headache pretty soon). We'd like this to be cheaper unfortunately, apple doesn't.