Does Vyrso offer discounts on their ebooks?

DAL said:

Do they? What percentage: 15%, 20%, 25%?

See for yourself: https://vyrso.com/products/search?q=&start=0&sort=savings&pageSize=60 

(mostly, in discounting books, Vyrso matches publishers' promotions)

DAL said:

Let me explain it better: Do they offer call in discounts, meaning, is it cheaper to call a salesrep than buying online?

The Vyrso bookstore is a highly automated process. There is no real team working behind it, and there are no specific Vyrso salesreps. The Logos salespeople are probably not aware of the Vyrso products at all. Vyrso books typically are very competitively priced anyway - I don't recall having ever heard of call-in discounts (but maybe there are very rare Faithlife-run promotions on Vyrso - but these would be announced very publicly, I think.

It is possible that a salesrep could give a better price in case the store erroneously doesn't carry the correct price for a publisher promotion, but in the normal course of business I'd expect the answer to your question to be: No