GE aux switch source of supply

I bought 6 of the GE 45609 switches, instead of the 3 way kits (45614). When I purchased I was thinking I could use my existing switches as the “remote” switch. Had I done a little more research, I would have realized that’s not so. I’ve been looking all over for the aux remote switches (45610) by themselves and they seem to cost almost as much as the 3 way kit. Does anyone have a recommendation on a source of supply of these switches or an alternate solution?