Cheaper satellites for RBS50 possible?

Hello all, I hope you are well and keeping safe...

I have an RBR50 and want an inexpensive satellite for taking signal to my wife's garage office. I can get a signal from a particular spot in the garage, but want to boost that so she could work in any part of the garage and have signal. 

I was looking at the much cheaper RBR20. Would that pair/work with the RBR50? As I say, I do not need blistering speeds, just something that works well, that does not cost £200 like the RBS50!

Thanks,

Mark.