When I went on the errand, I got a little reward.
I'll give you some sweets as a little something for helping out.
A tip in the Western sense, given for service at restaurants, hotels, etc. お駄賃 is more domestic and often given to children, not a standard service tip.
A reward or prize, often for achievement or good behavior. More formal and can be larger than お駄賃, which is typically a small, casual token.
Standard polite spelling with honorific お. The base word is 駄賃 (だちん), originally meaning a packhorse fee.
Formal or old-fashioned spelling using the kanji 御 for the honorific prefix. Rare in modern writing.
Honorific お + 駄賃 (だちん, originally a fee for packhorse transport). The meaning shifted from a transport fee to a small reward or tip, especially for children's errands.