You cant beat your own work, if you purchase or obtain a list of this sort from somewhere you have no idea how old or up to date it is and you’ll end up doing the same amount of work anyway in fixing it.
Nothing like attracting people to your site and giving them the wrong information, a sure sign that will see you commissions remain on zero.
Put the hours in and get the info and make sure you keep it up to date and you will see why it was worth it in the long run.