There are a lot of internationally recognized calculations and reporting methods and companies can hire consultants who can estimate the emissions in their end to end supply chains.
There are also calculators online that can give an example on what elements are considered, e.g. the below from UN.
Morgan recently did a video on handheld milk frothers at different price points (the milk still has to be heated separately), and found even the cheapest one at $5 to produce decent foam (with proper technique). If your kids are old enough to follow instructions, they might be a decent choice? Good luck on the search!
V50 user here (didn't get V60 cause of the larger size) I broke my phone a few months ago, filtered GSMarena for a replacement that'd fullfil my criteria, and Sony Xperias were the the best of the few options that it spat out. Ended up just fixing the V50 for $100, I too will probably hold onto this until it actually breaks.
Tetsu Kasuya's is my favorite recipe for the Switch! To me, it's easier than a normal V60 yet produces cups just as sweet, especially as I usually only dose 10g.
I guess it might depend on which Akibahara store you're going to, but at least a good number of them when I went this year (IMO) are just too 'generic' with a lot of the floor space dedicated to just the most popular franchises, with uninspiring merch (e.g. tshirts, acrylic stands) that can easily be found online.
Stuff in Nakano Broadway (where a large portion of the floorspace is dedicated to Mandarake's secondhand shops) are rarer and more diversified, and there's even a shop selling original animation cels of old anime (I was salivating over a Cardcaptor Sakura one which cost JPY500,000...). There's also the JOJO bar which is insanely cool.
I browsed r/JapanTravel a lot to look up tips and general recommendations.
The NAVITIME app is more reliable than Google Maps when it comes to transit planning. Plus, you can check the ticket prices including if you're using tourist passes (e.g. JR pass or local subway passes). Taxis are expensive af.
Tbh if you're not going in a big group, hotels are far more reliable than AirBnBs and their odd regulations.
Use coin laundry or washing machines in hotels instead of packing a lot of clothes.
Nakano Broadway >>> Akihabara IMO.