Age verification - selling vaping products

Hi
Has anyone got experience selling vape products through e-bay?
My last stumbling block is getting an Age verification put in place. Any ideas which is the best data base etc to use?
I’ve been given - 192 - VouchID and experian ID check to look into and just wondered if there are any others that are cheaper or wouldn’t it be great if FREE.
Or does one have to do these checks at all if buyer confirms that they are over 18?
I’d appreciate any info…
Thanks.