Search for what a first class ticket costs on your flight. The price is going to be that minus the cost of your economy ticket.

Snark aside, unless you're an elite you're probably not going to have a chance at check-in to pay to upgrade any of those flights. Those are all very high traffic routes with many (many) AA elites who get free upgrades well before check-in.

If you're talking about miles, you can check out the chart at https://www.aa.com/i18n/aadvantage-p...with-miles.jsp.