What are the risks (or options) of using box dye 2 months after having a salon dye?

I have died my really dark brown hair a pretty light red at a salon. I now have roots and no money to get them fixed. What can I do to keep from looking so trashy until I get more $$$What are the risks (or options) of using box dye 2 months after having a salon dye?
I say if your not comfortable using box dye


(dont do it!!)





but another option could be headbands


there are so many styles to choose from





if that doesn't work just be careful that you choose the right tone out of the box because most times salons custom blend your color and you dont wanna risk messing that up.