Hmm... economy is a bit I was kind of putting off as that would actually take a bit of work to do properly, but now that it's here, I'll put a simple bit out on my thoughts for it at the moment... not finished nor have I done too much testing to see if these situations are fully plausible. They should be.
10 coins is a peasant's monthly surplus minus dreaded tax and necessary purchases... in a good month. In a fairly rich country.
100 would be a lower end traveler's lot on average from odd jobs in town, enough to get a room for a couple days, pick up a 50 coin decent sword, pay for some meals.
1000-5000 would be a mid level merchant's monthly surplus in a good month excluding tax and necessities. Half that much would be the result of restocking a shop and paying regular stuff that comes up, including hiring a traveler for a couple days. 6000-10000 would be a particularly wealthy merchant's earnings in an average month.
10000-30000 is a minor noble or knight's yearly balance after getting money and paying for necessities.
Higher up nobles have up to 200000's worth to throw around in a year without special circumstances in a moderately wealthy country.
High nobles of wealthy countries can plausibly throw around 500000 easily a year.
1 million = today real world definition of wealthiest person in the world.