The Pulley & Belt looks OK; it is in Graham's video
Since the pulley and belt are clearly visible, these parts are not the issue at all.
One can unplug the washer and actually touch these parts if any doubt. The4 bonnet has already been "popped" since the video shows the pulley.
About the only things that can be wrong are the bearings, a cracked or broken spider, or the spider's bolts or welds to the basket are loose/broken. To see what is really wrong requires more than just popping the bonnet. It is more like having to take apart an engine or transmission in car.
To say what is wrong requires taking the basket out, a very massive job. Both a cracked spider or broken ball bearing will make the basket have massive "play".
Here in the USA having a tech come to one's house for a service call can be 60 to 100 bucks just to look at ones washer or dryer. To have one rip apart the machine to get the basket out would be another 100 to 200.
The real issue is do you want to pay a service guy 4 to 8 hours labor to fix this machine, plus parts cost. Most folks scrap the machine, since the cost is more than a new machine.
Doing it your self might just having you buying the 2 bearing and seal, and and gobs of time. ie the total fix can be less than 100 bucks if the spider is still ok. if the spider is bad you have to see if they sell just the spider; or the basket spider assembly too. In the usa some old sears machines have one the entire assembly and it might be 400 + bucks.
A cracked spider or loose one often will have a "looseness/play" that "maps" with the basket; since both are tied to each other. A broken bearing cage can have the play to be loose at all angles to the basket.
