There is only so much money for businesses to allocate towards labor, it is not infinite.
Eg: $15K per month for staffing translates to $3750 per week, which translates to $125 per hour at 30 hours per week on average, which translates to ~10 staff at $12 per hour.
At $15 per hour that is reduced to 8 staff. Alternatively the hours for 10 staff would be reduced from 30 hours per week to 24 hours per week.
The money doesn't come from thin air, raising minimum wage for 10 staff at $12 per hour to $15 doesn't mean there will be no layoffs or reduction in hours.
Increasing prices of products sold or services rendered would result in a reduction in products sold or services rendered. Again, the money doesn't come from thin air -- either prices are raised or staff costing is reduced through cut hours or cut headcount.
Who gets cut is another question too -- more than likely it is tied to appearance, education, likeability, or seniority. Who gets hired is another question too -- if the bar is too high for an uneducated black youth then they will simply not get hired. An increase in the minimum wage can result (and has historically resulted in) in higher unemployment among black youth.
A better way to think about this is for retail businesses the storefront landlord acts as a spring-loaded sink of money. The landlord will take all available money until the retailer has bare minimum margins, 2-5% typically. Retailers will trade away wages for rent because landlords are very powerful and retail labor is not at all powerful. Therefore the minimum wage is simply a way for the government to set a rule saying you can only trade down to this amount. To treat the staffing budget as a fixed thing isn't a proper model. You have to understand it as being in tension with other budgets.
It's a lot more complicated. Sometimes staff is set by the budget. Sometimes a business needs a certain amount of staff to function and can't get away with employing less. In a lot of cases, staff is set by the latter, and raising the minimum wage cuts into profit margins. It's potentially inflationary if product prices go up in response to higher costs, but often product prices are very demand sensitive and raising them will result in suboptimal net revenue. There is a reason a lot of studies show that increasing the minimum wage by small amounts has negligible effects on employment: there are many other factors to consider. That being said going from $7 to $15 in the US is an experiment for which there is little to no data, especially for rural effects (since only big cities seem to have tried it). I personally favor not having a minimum wage but only in a society with a UBI so you don't have people needing to make a living off what they earn in the labour market exclusively. In such a society people who's labour contributes negligible value to society can choose to do something other than work if they feel it would be a more valuable use of their time. People who earn a lot in the labour market still face a strong incentive to work. In current society the low-end employers appear to have oligopsony power which results in distorted downward pressure on wages, and many people are forced to take badly paying bad jobs in order to live.
This only holds true for places where there's no room to increase the staffing budget.
There are some industries where it might have an effect, restaurants/coffee shops in particular. But I wouldn't expect mass produced goods/foodstuffs to increase much if at all, simply because of how efficiently the labour is utilised.
There are also be potential productivity gains from having workers in a more financially stable position.
I'm sure Amazon isn't the only place that can afford to pay more, but they are definitely a great example for why our current economic system isn't fit for purpose.
Eg: $15K per month for staffing translates to $3750 per week, which translates to $125 per hour at 30 hours per week on average, which translates to ~10 staff at $12 per hour.
At $15 per hour that is reduced to 8 staff. Alternatively the hours for 10 staff would be reduced from 30 hours per week to 24 hours per week.
The money doesn't come from thin air, raising minimum wage for 10 staff at $12 per hour to $15 doesn't mean there will be no layoffs or reduction in hours.
Increasing prices of products sold or services rendered would result in a reduction in products sold or services rendered. Again, the money doesn't come from thin air -- either prices are raised or staff costing is reduced through cut hours or cut headcount.
Who gets cut is another question too -- more than likely it is tied to appearance, education, likeability, or seniority. Who gets hired is another question too -- if the bar is too high for an uneducated black youth then they will simply not get hired. An increase in the minimum wage can result (and has historically resulted in) in higher unemployment among black youth.