I used to toss any leftover loonies and toonies in my desk drawer at work, so I would have money to feed the vending machines. When the tin got full, I rolled a few and shoved them in the back of the bottom drawer. After about 10 years, my wife gave me heck when I brought home $2300 worth of change. Try that with dimes and nickels.
OTOH- I also helped count the local McDonalds charity donation boxes. They were typically 95% pennies (by weight). Between the insects that flew in and were trapped, and the pure garbage and food that people also “donated”, I had to run a money laundering operation before rolling the coins. Wash then in a colander and dry spread out on old towels. A 5-gallon pail half-full of pennies would be, IIRC, about $250. Pennies are useless. Australia and NZ were so much more sensible. Since the local McD went through so many pennies, they happily absorbed the rolls and passed a cheque on to the target charity. Recycling!
Canada’s PST has always been added after the price. The GST was supposed to be hidden, but the opposition accused the government of trying to pull a fast one by hiding the sales tax, so to be up front the government agreed that a price to be advertised did not require the sales tax included.
In fact, when the coins were introduced, Canada specifically stated that $1 and $2 bills could only be used as legal tender for the next year (or was it 2)? Then the banks would stop honoring them.
Canada used to have a $1,000 bill, which was a brighter red than the old $2 but easily confused. As you can imagine, they were pretty rare - $1,000 used to be real money back then - and still every so often there was an article in the paper about someone who accidentally spent one a a $2. So coloured money does not always help.
Maybe we should go to the old Italian system before the Euro, where the equivalent of a dollar was about 1,000lira. Almost every price was in equivalents of 100 multiples. I think I actually got a 50lira piece once - as change for a McDOnalds meal purchase.
Oh wait, maybe with current economic policies the US is getting there… There’s also the policy of the Zimbabwe and Sandinista Nicaragua economies - just recall the banknotes every so often to print 3 extra zeroes on them.