Rent a car though hotwire and the rental is still trying add fees. ?

I reserved a mid size SUV with Avis for $338.38 after taxes and Fees. So my co-worker told me to try hotwire and I received a better deal though hotwire for $197.38 after taxes and Fees. So now hertz website states that they need to place a $200 hold on my credit card. I thought if you used a credit card you hold would 25% of the total rental price not $200. Have anybody else every rent though hotwire using Hertz? I don’t want any more surprised.