In general if a clutch judders badly on trying to pull away particularly up a a steep hill, the first thing I would check for is any oil around the bellhousing of the gearbox, often if parked on a slope with the gearbox higher than the engine, or if gearbox oil level to high or merely of the oil seal and/or the bearing on the first motion shaft starting to fail, then oil can run onto the clutch plate.
This can start as a slight judder gradually getting worse, in extreme cases the oil will cause the clutch to slip.
The other possible cause is if the clutch has a mechanical fault, a cracked pressure plate or spring.
If it happened just after a new clutch had been fitted it can be caused by poor fitting, resting the gearbox on the clutch as fitting, causing damage, not something I have ever done in over 55 years in the trade , but I have heard of it.
In both those cases your are looking at a expensive job involving gearbox removal and replacement parts
Sorry I can't give price guide as have been retired from motor trade for several years.
Occasionally you can prove if oil is the cause at the early stages by deliberately slipping the clutch for 30 seconds or so trying to pull away up a steep hill to "burn" the oil off the friction material to see if eases the judder.
This will not cure the problem, merely help identifying the cause.
Re heavy duty clutches, unless you are carrying heavy loads or doing many stops and starts like a delivery driver, then a good quality clutch from a well known manufacturer should be fine.