Had an idea to pre-print barcode stickers for various items that ring up the product as something similar, but cheaper. Then slap em on as you shop and checkout at either the self checkout or with a cashier.

Not sure if a database of products and their barcode IDs for certain stores exists, but you could also make a trip to do the scanning. I'm sure we could find at least one comrade at each major store to leak a database of barcodes.

I prefer just leaving stuff at the bottom of the trolley than alt-scanning personally.

If I'm scanning groceries for somebody else then sure but if it's just my own stuff, it's not work. Take pumping gas, some locations do it for you but if I'm pumping it myself, I'm not doing work for fre.

Maybe, but this principle feels still reactionary in this case, depending on your presented solution. For now, we are more progressive towards our communist goals and better off with the self-checkout. It is a more centralized and efficient option in general. The problem isn't the fact that we are doing work for free that someone else should be paid for, it's that we should socialize the results of that free work in dropping prices and investing that labour elsewhere. Otherwise we're just re-privatizing the half of a process that's closer to socialization.

I don't think I'm necessarily complaining about your position here, you could just be using this phrase and agreeing, but I often see this phrasing followed by the reactionary "we can finally have normal lines and clerks like we used to have". Giving them that job back now (in full amounts, like before self-checkout lowered the amount) just results in even lower pay for those people and decreases every other benefit from it. There's never a going back in these cases which won't result in much worse things and further from a workable position strategically..