If you don't mind getting you fingers greasy, you can go for the cheap option of:
Remove the bearing cage and just packing the headset race with new ball bearings of the correct size (just measure what was in there originally), leaving about as much space as one balls width empty.
Packing the headset with as many balls as possible is a standard trick used by MTB'ers to make the headset to take more/bigger knocks. The headset may not last as long in normal use (i.e. riding on the road) as the bearing will rub against each other rather than the softer material of the cage. However, if you look after the headset and replace the balls now and again it will be a lot cheaper to buy a set of ball bearings (a couple of quid) rather than replace the whole headset.
If you don't mind getting you fingers greasy, you can go for the cheap option of:
Remove the bearing cage and just packing the headset race with new ball bearings of the correct size (just measure what was in there originally), leaving about as much space as one balls width empty.
Packing the headset with as many balls as possible is a standard trick used by MTB'ers to make the headset to take more/bigger knocks. The headset may not last as long in normal use (i.e. riding on the road) as the bearing will rub against each other rather than the softer material of the cage. However, if you look after the headset and replace the balls now and again it will be a lot cheaper to buy a set of ball bearings (a couple of quid) rather than replace the whole headset.
Put plenty of quality grease in.