For a birthday
The minute of the year that is theirs.
For the person who says not to get them anything.
Pick the minute it happened, put their name on it, sign it from yours. From $9.99, and $19.99 for the plan that adds the certificate.
Why this one works
The hard person to buy for is not fussy; they simply have enough objects. The way past that is to give something that is not an object and is still specific to them.
Their birth minute is the most personal number they have and one nobody has ever given them. It comes with a card you can send from anywhere and a certificate you can print at home an hour before the party.
If you do not know the exact minute, ask their mother. She will know, and the asking becomes part of the present.