I didn't really spend any time analyzing ease of use, but at a quick glance, I would guess that the base is 100, with a delta of -0.3.  So hitting 30% gets you to the magic 90 med use.

Duration:

The stated duration formula is correct.  The duration formula always looked suspicious to me (I would have expected a 66/33 split), but the documented 60/40 split is correct.

The effective Duration formula is (6*Avian DR + 4*Avian OQ + 6*Gas DR + 4*Gas OQ)/20.  Nothing fancy here.

Duration runs from a base 1200 with a delta of 130 (so a range of 1200 to 14200).  This fit the data remarkable exactly (the actual result within 1 of the expected result when the line was maxed out).

Power:

The effective formula is (Avian OQ + Avian PE + Gas OQ)/3.  Again, the avian PE is overweighted since the gas has no PE.

Power runs from a base of 40 with a delta of 7.6 (so a range of 40 to 800).  CDRM, BEC, and SDD power are added to the final result (once for BEC and CDRM despite there being 2 or more required in the schematics).

The crafting process:

We know that duration and power are on the same experimentation line.  We suspected that a separate "role" was made for duration and power.  I confirmed this was the case.  There were multiple times when I got a "great" success, yet duration would increase at an "amazing" success rate (at 8% rather than 7%) and power would increase at the standard 7% rate. 

The displayed percentage value is some sort of average of the duration and power experimentation.  This is why once you max out one line, you can continue to experiment, but a "great" success yields less than 7% (displayed... it still applies up to 7% to the line that still isn't maxed out).  As a result of this, do not use the displayed percentage to calculate power or duration.  To test the formula, max out the enhance pack on a clean experimentation run (no crit fails), and compare the final results with the theoretical results with the resources and subcompoents you used.

A great success isn't always exactly 7%.  The duration grew at a reasonably consistent rate when experimenting a point at a time, but would sometimes be a little off (more than 1, which one might expect from rounding, but less difference than 130 in duration, which one would expect with a moderate of amazing success).  In other words, there are still a few things that happen under the covers that I don't understand.

OK, now back to the question, "how much is that avian worth?".  Based on the formulas above, we can conclude that:

100 Avian OQ (or 100 Gas OQ) is worth a maximum of 0.67 charges, -1 med use, 260 duration, and 25.33 power.  It's worth about 30% of that on a line that isn't maxed out (in starting values).

100 Avian DR (or 100 Gas DR) is worth a maximun of 390 duration (and 30% of that if you are crazy and don't experiment the effectiveness line). 

100 Avian PE is worth a maximum of -1 medical use and 25.33 power.  Again, it's only worth 30% on any line that you don't max out.

As a point of comparison, the difference between a pack made with a 500/500/500 (perfectly average) avian meat and 900/900/900 avian meat (which would sell for 200 cpu presumably) with all other inputs being equal would be -2.4 ease of use (maybe 1 less experimentation point to get it to 90 if that's important), +0.8 charges, +202.67 power, +2600 duration.  This is assuming that the effectiveness line is maxed out and any extra points are put into charges or ease of use, but neither of these is maxed out. 

In monetary terms, what is an extra 202 power (500 or so on the actual buff), 40 extra minutes, and an extra charge worth?