I think if you include the cost of an iphone then it's probably more expensive then the alternatives (unless you connect it to your own iphone/account in which case Apple will happily give your details to the police if the Airtag is found). I think the bigger problem is that if you're being tracked and you don't have some iDevice plus someone has tampered with the airtag speaker you're not going to be notified of its presence unless you install and use the airtag scanner app, which is a poor solution in my opinion. I'd like to see them open up the mesh protocol at least enough so that Android or other devices could see tags near them/be notified if they're being followed without having to opt-in