Previously/before

They are OK.

User_garyPreviously, they were giving $50 per day, but now they are offering only $25. Usually we expect the verb to be the same, because the time period and amount are being contrasted.

Before they were offering $50 per day, but now they are offering only $25. The use of "before" in this position leads the reader to expect it to be a subor

Thanks a lot Alpheccastars. It's indeed a great explanation.

User_garyPreviously, they were giving $50 per day, but now they are offering only $25. Usually we expect the verb to be the same, because the time period and amount are being contrasted.

I can't understand what you mean here. Do you mean I should write "previously, they were offering $50 per day,

The verb does not have to be the same tense, but the verb itself should be the same. The original had "giving" / "offering". It is OK, but diminishes the comparative effect because the reader has to figure out if there is any difference between "give" and "offer, or only the time and the amount.
Previously they paid $50, but now they are paying only $25.
Company X

Hi. Would this be OK for the original poster's sentence? Please look at the punctuation.

Before, they were offering $50 per day, but now they ar

e offering only $25 per day.