Choosing 8×25 or 10×25 comes down to reach and viewing margin
Choosing between 8×25 and 10×25 binoculars is not a choice between a basic option and a free upgrade. When the objective diameter and body stay compact, 10x gives more image scale, while 8x usually preserves more viewing margin through a wider field and a larger exit pupil. A current same-family comparison makes that trade easier