As for price, have you looked at R2B? They're 247 as of right now while I'm at 249 and I include the ability to post CSV datafiles which, for R2B afaik, requires a separate product priced at 97. And, TBS is currently at 207 and they only got around to supporting their own blog which they're fairly excited about for some wacky reason. I'm being facetious about purchasing these two products: check their non-refund policies before even beginning to consider them and then compare it against my own.
Anyway, I'd recommend purchasing CF around the first week of October. Then, I'll be releasing CF Professional Edition which adds in features and I'll be adjusting the pricing scheme to sell the software separately from support. I'm doing that b/c most customers never need support. Only about a dozen have legitimate needs for support and of those half are just total morons. The other half are just trying to wrap their heads around some of the concepts and need some extra guidance. Yet, all those other people pay a price which includes support as part of it. I haven't settled on the pricing difference, but if you want to proffer a suggestion, I listen to them all (which is different than using them all, so don't be offended if I consider, but reject your suggestion).
Now, on to your other questions:
Do you have an option to mix the content from different sources and create a single post?
Yes. You can mix the following types of content sources:
Articles
These are formatted as shown here and are posted in random order.
Code:
#TITLE#My 1st Article Title#/TITLE#
My 1st article body
#BREAK#
#TITLE#My 2nd Article Title#/TITLE#
My 2nd article body
Saved Posts
Just like articles except that the order is sequential.
CSV
Basically, just CSV formatted files with certain header requirements. You can create as many HTML layouts as desired to vary to look and feel of each post.
Keyword CSV
Same as CSV except that the first column contains the keyword for which that line is valid. When a keyword is chosen for a post, only those rows containing the same keyword will be considered for posting purposes. Again, as many HTML layouts as desired.
Paragraphs
Text separated by line breaks. Just like if you were typing in Word. You could put one sentence per line and then choose to use 3-5 lines at a time to dynamically create paragraphs of text. Not the slickest form of rewriting, but a form of it.
Text Only
Just like paragraphs except the delimiter is #BREAK#
RSS/ATOM Feed Reposter
Reads RSS and ATOM feeds for reposting (i.e. posting the entry once and only once, so you're basically posting all the content available in one feed to another site w/o repetition).
For all those listed above, you can choose one of 2 options: To post only that specific content source or to post all those not set to posting by themselves. So, you could, for instance post an article one time and a mix of paragraphs and RSS another time. What this does not include is the ability to post articles and paragraphs one time and then a saved post and CSV entry another time (the limitation being having more than one setup with multiple content sources).
RSS/ATOM & SE as separate sections
All the options above are in the content section of CF Pro. There are 2 other sections (a section is a grouping of content managed completely separately from the other 2 sections) which allow you to post RSS/ATOM feeds (totally random, so not reposting) or search engine results. These are fairly straight forward.
The above description is valid for Content Farmer or Content Farmer Professional Edition. In addition to that described above, CF Pro will allow #CATEGORIES#Category 1, Category 2#/CATEGORIES# within the content source to override the project settings for categories. For example, you could post articles to a specific category instead of being confined to having one of the project's categories used at random (which is currently the case). You also won't have to stress as much on the file format in CF Pro as I'm adding in a file editor which will correctly format the files and give you the ability to edit them.
Also, for each post, you can define one or more sections of text/javascript to prefix or suffix the post with.
Also is there any content rewrite engine (like markov) other than just replacing few words?
At this time, for the content sources other than the last mentioned above, you can use tokens to replace text. A Markov module may be made available in the future. I'm working/testing the math of that in the next few months.
Well, I think that fairly completely answered your questions. Let me know if you have any others.
I'm glad I found these forums. While I've posted only on my product, I have been reading them and it's helping to know what others are doing so that I can turn my attention to the other methods available.