If your current lease is terminated and a new contract will be signed, the new rental price has nothing to do with your current rental price.
If your current lease can be assumed by the new owner and you all agree to continue the current lease, the price may not change.
If you are in arbitration, probably with a retired judge, the other party has the right to refuse to provide information about the house sale and even may reject the arbitration.
There are too many details. You need some law professional to review your case and give you advice.