Even my WagonR has same problem and I got it done in following way-
1. Replace stabilizer bar
2. Replace lower arm (R side in your case)
3. Weld the aproan where there is crack.
1+2+3 costs about Rs. 3000. FYI
, if apron developes crack, it also means above 1+2 are also damaged. If we can get desired results with 1+2+3, why to go for apron replacement.
I am running my car in this way for last 3.5 years.
I have a older gen WagonR (not the blue eyed boy) and I was quoted 8.5k for replacement of the apron by MASS. (Not those big guys but smaller MASS in Pashan).
Where do you stay in Pune. I can try to help you in getting it done with least damage. (I don't own a garage nor have any contacts. But I can assess your car and possibly advice you as I have gone through the same problem.)