Is there any way in which i can set a particular 'percent' of discount in all of my listed domains ?

I have around 1000 domains listed at uniregistry marketplaces and at times when i am facing cash crunch i want to offer like 30% limited period discount on them. So going to all domains individually and changing the prices is so tiring and time consuming.

So therefore i wanted to know if there is any feature through which I can offer a particular percentage of discount which applies to all the domains and reduces the prices proportionately in one go.