What is the best source for prospecting national STNL leads?

[Christopher Torian]

Good afternoon! This is my first post on the forums. I am a commercial real estate broker looking to get into national single tenant net leased investment sales. I am wondering what the best source for getting property ownership information would be? My office currently has a CoStar subscription, but only for our regional area. Are there any other (hopefully more affordable) options to gain access to information for STNL owners? 

Thanks in advance for your help!