Jess,
That's quite a basket of gear of varying pedigrees.
I've heard a lot of it in different places and different times, never all together. But what the heck, I'll weigh in.
Speakers - the Paradigm v100.5's are well regarded and sound very good. I've heard them in a friend's HT setup and they acquit themselves very well. They have good in room response and imaging. Their sonic signature leans toward the forward / bright side. The Audioengine P4 are great little speakers for nearfield listening. They do not play loud.
I have not heard the 15" Epik Subwoofers. They have the juice to be great HT subs and have been positively reviewed. Epik came on the scene a few years ago as a value leader, had serious QC issues, and is now out of business.
The Paradigm DSP-3100 10"s driver is too small to be considered a real sub (by me, anyway
) It may work in a small room.
Emotiva stuff is loved and hated, reviews are all over the map. Lots of fanboys and haters. I've heard the Emotiva USP-1's driving a set of Polk Audio floorstanders at a co-worker's house. Sounded very good, great Bass, but tended to be on the lean/bright side.
Marantz Pre/Pro's are generally well liked and the reviews are generally positive. The 7005 is now obsolete, not having 4K and the latest audio decoding options, if that is important to you.
DAC, CD player, converter, receiver;
A real dog's breakfast here. Everything is outdated and pretty much worthless in today's market. Nothing to see here, move on. For example the DAC's in the Marantz 7005 are likely better than the Emotiva standalone DAC. I say that with a grain of salt, not having heard either.
This all makes it hard to value.
What are your goals? If a high quality 2 channel system is in your sights, you'll end up with a mid-fi system and quite a lot of gear to sell, much of it worthless.
If you are looking for a competent 5.1 system and are not interested in the latest audio/video formats, the Paradigm/Audioengine/Epik/Marantz 7005/Emotiva UPA-X system would make a good foundation, assuming the addition of a high quality disc spinner like the Oppo 105. You could start replacing the weak links over time.
One way to approach this is to determine the used values of the pieces you want and offer the sum as a package price to the seller, discounting everything else based on what you think you can move it for, probably less than $0.10 on the dollar.
As others have stated, an intentional, focused acquisition strategy will serve you well and allow you to build a best-in-class system over time.
Regards,
Tom