This is where you say "my total compensation is around $x". To me, "total compensation" includes pay, benefits, bonuses, the dollar value I put on how short my commute is, rough cost of free food in the office, how nice my chair is, etc. etc.
I also don't think they'll be able to do an equifax/transunion lookup without your permission. And it's perfectly reasonable to say no to that, as credit checks are bad for your credit.
"Well, I guess Eqifax is not that accurate" and "Oops. Thanks for letting me know I don't want to work here" would both be reasonable responses. Most companies are not doing this.
I also don't think they'll be able to do an equifax/transunion lookup without your permission. And it's perfectly reasonable to say no to that, as credit checks are bad for your credit.