I do not see a problem with Discounted prices. Yes, you will loose earnings for a time on that item but in the long run, you will gain more notice to your portfolio and item/s. It's the same as giving a free item.
I wish there was also a FREE option so that I could promote a Free item outside of the regular Envato Freebies
Marketing is tremendously important for digital files when don e properly and discount and freebies does affect your sales.
I tried it on another marketplace - gave a few items fro free and at discount prices - sales were booming. Removed freebies and discounts for a month - Sales dropped.
Started the freebies/discounts again - sales started to boom again.
Additional marketing helps like a blog, twitter, facebook because buyers will need to know about the sales/freebies
when they come some will grab and run while others will grab, buy and follow. These are the buyers you are working to get.