Never mate!
To be honest I don't use boilies that much, except for the occasional carp trip and as a change of bait for tench, barbel and chub.
I only use boilies for hookbaits and the odd freebie, I still have plenty of hookbaits left from the kilo bag of A8 I mixed up 2/3 years ago.
I always felt, and maybe I am wrong, that Nutrabaits looked expensive but apart from that many many anglers on this forum, and others, swear by mainline!