Accept the position or don't
use his recommendation letter. Actually, why let your friends supplely accept the position and go back to that position? Since anyway his salary is low. I don't think there is any difference between 3万多 and 3万多 + 40%.I don't think it's worth to 得罪前老板 for only 1万多. Later on when you get GC, you will find, 1万多 is just a piece of cake, and is too easy to make.