What would you choose
it is a laptop
Both are not enough for my application. Less than 512Gb is no longer appropriate for a laptop.
Without knowing what you are doing with it, however, you can't give any advice. At 128Gb with Windows 10, you can't really install a lot.
With this massive price difference, more components are guaranteed to be different.
What kind of laptop is it? If you can swap the hard drive yourself, or in general swap it, I would prefer the cheaper laptop and install a larger hard drive there. Even as a layperson, this can be implemented relatively quickly and easily.
The surcharge of 200 euro is simply disproportionate for just 128GB more storage. For 200 euro you can get a good 2TB SSD.
Otherwise, I would advise you to use the larger memory variant, since 128GB are simply used up very quickly. Windows itself needs almost 40-60GB of memory and if you have a few more data on it, you will reach your limits very quickly, even at 256GB.
The surcharge of over 200 EUR for 128 GB more is madness.
You can also find good notebooks around 700 EUR with 512 GB. On the other hand, I consider 256 GB to be the absolute minimum, especially since the operating system also takes up space.
Can the cheaper model be upgraded?
Then take it and install a 512 GB SSD.
https://www.alternate.de/html/product/1463306?partner=goadwoPLA&195.234.50.2
If you don't want to save videos. All you need is space for emails, documents and a few pictures.
If you have other requirements, then of course 256GB
The first, because you don't need much more anyway and if you do, you can buy a USB stick that costs 10-60 euro.
The question is whether only the storage capacity changes.