Odinterimon

Hi Guys I have recently hit a pot hole near the size of a football with the off side front wheel and the result ( I think) has been constant knocking at low speeds while parking or turning and over rough roads. It has got slightly worse over the last few weeks, so I had my local garage near where I work take a look as it was due an MOT any way. They said they could not find the cause and the mot was passed with a note to get the drop links done as slight wear on both sides. The drop links have now been done, the garage looked for the previous problem with the knocking and found what they think is the cause, slight wear in the o/s/f lower suspension arm outer ball joint. The quote from Nissan was apparently the cheapest @ £256.18. This is for my model JDM as they are different than UK issue? 3 days to order and £110 labour + vat and we have an eye watering £439.42. As I have just shelled out £250 plus on the drop links etc its on hold atm until I find out if this is a good deal or not? These guys are not Nissan guys but seem to get the job done and as its next door to where I work its an easy drop off. Thanks in advance for any help or enlightenment