I'll echo @MichaelMaggs - this is certainly too broad.
A few things I can think of without particularly trying:
A business buys cardstock, adds value by printing advertisements/flyers/coupons on it, and gives it away for free to attract clientele.
Someone buys blank CD-R media, adds value by burning songs on it (mix tape or demo tracks), and gives it away for free to friends, family, love interests, or recording studios.
More generally, pretty much everyone buys stationery or postcards, changes them by writing on them (and debatably adding informational if not sentimental value), and then gives them away for free to whomever they wanted to send them to.
Or, even, any of these gift card holders, which you purchase, add value to by putting a gift card in, and then give away for free as a gift.
Pretty sure you need to narrow this down a lot. "It's not sufficient that your intended answer fits all parts of the puzzle. If many answers could fit, then the puzzle is under-specified. A well-crafted puzzle will give enough information to rule in the intended solution while ruling out everything else. Also, potential solutions should be testable by referring to the puzzle, not by needing a response from the setter as to whether they're right or not. If the puzzle lacks enough specificity to make that determination, then it's probably too broad" and likely to be closed as such.