Whats wrong with your guys boots? if it is by any chance the SPK and it is the internal lace that blew out on you then many of the snowboard laces that they should have extras at the shop should work for you. Ive also had the booster strap blow out on them before and i just had it re-riveted with a new washer . I have also had the spoiler at the back blow out on me and was able to get a new set shipped in by the shop who said one of their sets of boots was missing some.
And all of these things were able to be just done at a shop. Unless it is something catastrophic there is a way to get it fixed on the cheap.