Honestly they might not CRASH crash the economy but I honestly think they could do some serious damage. At the very least if Amity is going to start essentially printing USD with these cards to get infrastructure and the like set up the inflation within the town is going to go crazy and they might just need a new currency.
I think it's also determined by how LARGE you consider Amity to be. As I've always seen it described as a small town I've always envisioned it to have a population of around 10,000 people.
AS IT TURNS OUT the wiki describes it as 'Amity Park is depicted as a moderately large urban city, reminiscent of Chicago, San Francisco, and/or Philadelphia'
WHICH IS WAY LARGER THAN I IMAGINED. I don't know SHIT about American cities or their layouts apart from the fact that Everything Is Squares and also apparently the junctions are death(? Apparently America doesn't have roundabouts??? Bro??? I don't know if that was a Simpsons gag but I think about it maybe half as often as I use roundabouts), BUT the point is that google says those cities are somewhere around 800,000 to 2.6 million.
Honestly I think those are weird numbers because those are enough of a range to not be at all considered the same size imo but we'll take Philadelphia as our base bc that's the one in the middle at 1.5 million.
In "Amity Park's" population statistics (X) if you take everyone from 20-44 (we're pretending people under 20 can't get one bc apparently 13 year olds can get them with special permissions and that fills me with a special kind of anguish to have learned) but if you take everyone from 20-44 that population totals something like 613,028.
We'll give an error margin of 10% to account for people who are auto disqualified for whatever reason and between that error margin and the people I'm ignoring I think it's realistic to assume you could get 551,726 people credit cards. Unlimited ones? maybe not. But look me in the eyes and tell me if Sam Manson was told 'We can fix the public infrastructure that's damaging the environment and cause serious damage to predatory lending companies' She would not use her families wealth to be backing people as some kind of collateral/co-signer to get OBSCENLEY high credit cards SO FAST.
That's to say nothing of if Tucker and the Other Nerds decide it's actually completely fine for them to hack into these companies and auto approve all these credit cards. Like the towns in dire straights so why not? It's unfortunately a pretty human tendency to see the people you care about in trouble and decide you're willing to throw literally anyone and everyone under the bus so I can see him/them doing it.
So. 551,726 people, with theoretically unlimited money to spend.
CONSERVATIVELY if they racked up $500,000 USD on each card, the amount of money spent by Amity would end up being $275,863,000,000 or $275.8 BILLION
Now the GDP of the USA is $25.44 Trillion, which looks like $25,440,000,000,000 so it's not a LOT in the grand scheme of things but it is just over 1%, I'm not going to pretend I know what that does economically to the entire USA but consider that Beer sales in the USA accounted for $106 billion in 2022, and that amity would potentially be generating nearly three times that. (X)
I have just gone on a fucking TANGENT about the economy in this silly fun times thread of ours so I apologise I will try and sum up very quickly why I think they could spend so much so quickly.
Philadelphia has a total of 37 hospitals. They built a new one sometime around 2021 to the tune of $1.6 billion (X)
If Amity built a new hospital for liminality care and a few new ones Just Because They Realised They Can, say they build ten new hospitals, which is a VERY LARGE amount of new hospitals to build on workforce Alone, but they probably have tireless ghost workers who are probably obsessed with construction and regular living workers who want to be paid in the times before everyone had acclimated to the ghosts properly.
Split among 551,726 people that's actually a fairly reasonable $28,999.90, which, hilariously, is actually just in and around the average limit to credit cards. So they wouldn't even need Sam or Tucker to mess with credit cards yet (X)
Averages typically suck as a way of measuring stuff but this isn't a Real Life Government Project so I'm willing to call that acceptable. So if it's only $30k for ten hospitals why the hell am I citing a fat $500k each?
Luxury Shit.
A few luxury cars and some big name watches and you've blown through that $500k no problem. That's to say nothing of all the REST of the infrastructure that needs fixing - the roads, the schools, the libraries, the replacement materials for the transport system - hell building the APDC is going to probably be another billion dollar project if they want two portals large enough to get what is probably multilane traffic through in regards to transport. Sure the cars won't be useful for long maybe but that's just one example.
Jewellery, coats - hell designer shoes and collector nonsense can go for STUPID amounts and as people who are desperate to outpace their neighbours in Cool Stuff They Own realise that their neighbours are capable of getting all the same crap they are? people are either going to stop caring or they're going to start buying some Really Obscure Shit.
For the others who just wanted to buy pretty things? There's literally no reason to stop. Amity might have to limit the amount of crap people can get shipped in per week/impose serious shipping tariffs just to make sure the new FTL supply chain doesn't collapse because people are determined to get their new Cashmere and Mohair coats with Gold Embroidery or what the hell ever on next day delivery.
Honestly in this scenario the cards over time thing probably doesn't matter because I'm pretty sure the Amity expenditure would DESTROY the lending company, which might then actually be the thing to get Amity rediscovered or maybe they space all these buildings out over time so they keep living the sweet life.