If you want a stand mixer, just get this, you won't regret it. Other brands are simply not up to par.
All base units are the same in each range, the different codes are for different attachments in the box and only certain colours available in each. So the 125 is this without the pouring shield, 150 has the pouring shield, the 175 comes with the pouring shield and an extra beater with a rubber bit on it, 185 has an additional smaller bowl on top of the stuff the 175 comes with.
What is the difference with 5KSM125? This one seems like not exist kitchenaids website
Good price for a 4.8l if it also comes with the pouring shield.