38 Gargraves switches. Same issue, as you, with Ross they are very expensive. I replaced all of my Lionel O27 tubular track switches with Gargraves. And they have given us an excellent, affordable, product.
Edit - Installation depends on your track. It is a tubular product and mates well with O27 and O and they sell pins to fit. You might have to do a little shimming. But, the installation is straight forward and they have very good directions.
Yes they do run independent of track power and use accessory power. Or you can get use the manual ones and they don't use any power....
They best buy, for in the package Gargraves, I have found is wholesaletrains.com.