I am enthralled by the smallest claims (quantum of damages requested at the outset) that reach, and gets decided by, Commonwealth apex courts. I am NOT referring to the apex court's award of damages, particularly nominal damages, because the apex court might have shrunk it from the damages originally in the prayer for relief.
These private law cases claimed the teensiest quantum of damages adjusted for inflation in Canada, and England and Wales. Correct me if I missed cases with even teensier quantums!
England and Wales. £50 in ParkingEye Ltd v Beavis  UKSC 67.
Mr Beavis left his car in the car park for longer than the permitted two hours of free parking and was subject to the charge—£85, reduced to £50 for prompt payment. He refused to pay this sum and was sued by the parking company, ParkingEye, for breach of the parking contract.
Robert Merkin, Poole's Textbook on Contract Law (2021 15th edition), page 595.
USA. $1 in Uzuegbunam v. Preczewski (2021).
In this relatively cabined context of constitutional rights, Uzuegbunam’s holding may have the practical effect of keeping otherwise moot cases alive where the plaintiff “tacks on a request for a dollar.”
[P]rovince was able to recover $300 from a driver who damaged a roadway. This one is probably the most on point to your question.
DICKSON J. — The question is whether the sum of $300 received by Elizabeth Joan Savage from her employer, Excelsior Life Insurance Company ("Excelsior"), for successful completion of the Life Office Management Association series of examinations, is subject to income tax.
If you go back far enough and don't care about inflation, you can get down to $100. See Joyce v Hart , 1 SCR 321.
Not exactly on point (not a damages case), but I also found Trial Lawyers Association of British Columbia v. British Columbia (Attorney General), 2014 SCC 59. There the court was asked to determine whether a court hearing fee (the fee paid to the court to schedule the trial) was constitutional. The hearing fee in the case that was appealed to SCC amounted to $3,600.
$5100 CAD in City of Vancouver v Ward 2010 SCC 27.
Justice Tyson awarded damages in the amount of $5000 for the strip search and $100 for the seizure of the vehicle pursuant to s 24(1) of the Canadian Charter. The B.C. Court of Appeal and the Supreme Court subsequently upheld this decision.
I stumbled upon Vancouver v Ward at footnote 7 on page 785, in Roderick Bagshaw's Tort Law (6 edn 2018).
See Att-Gen of Trinidad and Tobago v Ramanoop  1 AC 328, at ; James v Attorney General of Trinidad and Tobago  UKSC 23, at ; Inniss v Attorney-General of Saint Christopher & Nevis  UKPC 42, at ; Vancouver v Ward  2 SCR 28 [emphasis mine], at –; Taunoa v Attorney General  NZSC 70, at , , .