B cam?

My main body current is a Sony A7IV, i plan on getting an FX3 by the end of the year. My previous cameras were the GH5 and BMPCC4k. I still Currently have them and I’m looking to sell the GH5 in hopes of getting a B cam that’s relatively inexpensive because it would just be used for vows and toasts.

Should i keep the GH5 and use it as a B cam or sell it and get a Sony ZV-E10 as my B cam?