The front wheel of my bike started to feel slightly unbalanced a week or two ago.

Now at the low rpm's there's a slight feeling of drag, like there's someone behind holding onto it and trying to unsuccessfully pull it back. It's only very slight though.

The front brake rotor was changed around 25,000 km ago.

I don't think the front axle or bearings were ever checked. Bike has nearly 80,000 km on it. Possibly them?

Is it typically cheap to replace an axle, bearings and seals (and anything else that is in them?). Bike is a used 2011 CBR250.

Any advice on what else it might be before I take it in for them to check?

I like to have a little list of things for them to look at and report back on.

You say it feels unbalanced does it vibrate? Or is it felt through the brake lever?

You say it feels like someone is holding it back? Have you tried rotating the wheel ( maybe with a friend) when the bike is on the stand?

To answer the direct question it is quite easy and cheap to change the wheel bearings. My rear ones failed at about 15 years but odo only says 18,000, so at 80,000 it is probably time to change both front and rear.

As said it's cheap and easy to change the wheel bearings. Try that 1st and see if it fix the problem.

Sent from my mobile, whatever mobile it is.

Wheel bearings are a DIY job for someone with moderate skills. New seals should be used as well.