The pulleys don't really wear, they are steel, versus rubber on the belts. To consider wear on the pulleys is like considering wear on a knife that goes through butter. But the pulleys do have bearings that can wear and if bearings are worn they can make a noise. However your symptoms point to the belt(s) slipping on the pulleys, and since this happens just after engine start it points to the main belt slipping on the alternator. If the belts are in good condition it all points to lack of tension on the main belt that drives the alternator and PAS, particularly if the bearings don't seem to be at fault (and I doubt it is the bearings you are hearing, it will be belt slip). The other (shorter) belt only drives the AC compressor so this can easily be ruled out by turning AC off, but in any case the fact that it squeals after starting the engine points to the belt that drives the alternator.
By rule of thumb you should be able to twist a belt 90 degrees using only moderate hand pressure along the belt's longest free length, om Elgrands it seems to pay to err on the side of a bit more tension to prevent belt squeal, the distance between pulleys is comparatively short and there is no spring loaded tensioner fitted that might otherwise take up slack on unloaded sections of the belts. There are 2 belts and neither drive the water pump, hence 2 short belts, hence more tension is needed than might otherwise be expected.
The tension adjuster for the long main (alternator and PAS) belt can be accessed by removing the plastic access panel for changing the oil filter. The tension adjuster for the shorter AC belt can be accessed without removing anything by inserting a 12mm socket on medium/long extension from the passenger side of the front plastic undertray.
Don't pay the garage to change pulleys ;-)