Xfinity Mobile $250 promo for BYO device

​​​Back in December and early January, I saw a Xfinity Mobile deal for a $250 promo per phone if you bring your own phone.​​​

​​​Now when I check it is $100.  How often does Xfinity do the $250 promo?  Is it once a year event or does it happen more often?​​​

​​​Looking to move from Verizon to Xfinity Mobile, but not in a hurry.  So if the $250 deal comes again in a few months I might wait for it.​​​

​​​Thanks,​​​