The current/today's dynamic pricing for "rewriting" jobs:

Traditional "re-writing" (CopyScape, DupeFree Pro etc):
Per nominal 500 words: INR 100 (about US$ 2.50)
Same number of paragraphs and nearly same word count. The sense does not change only sentences and words are different. No research involved!
PS. This is putting old wine in new bottle!

Complete "re-wrting" to ORIGINAL:
Per nominal 500 words: INR 200 (about US$ 4.50)
The new article will appear on Internet as -
New wine in New Bottle!
Basic idea is the same as original however the song sounds very different.
People reading this piece will always say that this was a" Singer Not The Song"!
Research may be involved.

Dynamic pricing is the essence of good ecommerce and is the normal method of marketing goods or services on the Internet.

The best example of dynamic pricing is shown in Make Your Price Sell or MYPS! This is a program and e-book that is run by:

Make Your Price Sell!, The Masters Course

Following which you can go to:

Make Your Price Sell!

The program is awesome as it will inform you of the best way to arrive at your pricing decisions. Have a look at the above pages and decide for yourself!