Hi there,
You do have a lot of options so it can definitely cause confusion - sorry!
I'll try and explain based on your two options:
Option 1: Currency Events:
Currency events (as shown here: Compare counter, incrementor, and currency events ) are basically just regular events that can accept 2 decimals and are formatted with a $ dollar sign ahead of them in the interface. In Workspace, the data would look like this:

Both of these metrics are currency events.
* You'll notice that the decimals are not shown by default. If you need decimals, you can create a calculated metric based on a currency event and add decimal places there.
* You'll also notice that the currency symbol is shown based on the report suite's Base Currency setup. That's why these two metrics show a USD $ rather than a Euro or GBP symbol.
To implement currency events, you do not have to use the products variable if you don't want to. You can simply set:
s.events="event2=9.95";
and event2, if it's a currency event, will receive $9.95.
Option 2: Using Products:
I'll be honest, the products variable is complex and difficult to use. Everyone gets tripped up here, so you're not alone if it's confusing.
Unfortunately this is a bit of a necessary evil because, as you mentioned, some companies have thousands of products that need to be tracked, each with individual metrics for revenue, units, discounts, tax, shipping, and more. So that's why it's so complex.
If you want to use the default "Revenue" metric in Adobe Analytics, then you *must* use the products variable to send data to it.There is no other way to capture data in that metric without using products. The advantage to doing this is you can apply revenue metrics to product SKUs, rather than eVars. There are some significant advantages to doing this, especially when multiple products are being purchased at the same time - product A costs $40, product B costs $10: using the products variable ensures that each product receives the correct amount of revenue. If you were to set these in eVars, you couldn't properly distinguish them unless you used different events too.
Here's the syntax (as described here: products 😞
s.products = "Category;Product;Quantity;Price";
Let's break down the individual fields:
Category is generally ignored since you have more control using Classifications. Therefore, the products variable syntax usually starts with a semicolon.
Product is the product name/sku that you want to pass in.
Quantity is the total number of units being purchased
Price is the total number of units times individual revenue per product purchased.
You can also send product-specific events and merchandising eVars here, but that's a whole new can of worms that I don't think you need to worry about just yet. For a good merch eVars reference: (https://analyticsdemystified.com/adobe-analytics/merchandising-evars-omniture/ )
Populating the Revenue metric also requires sending the purchase event:
events="purchase";
I hope that helps!