It definitely proves that parting out by auction is not profitable on the LOTR sets.

if you are selling partial sets or whole sets how do you determine your pricing? I'm sure experience comes into it but on a set like your example what helped you pick your $49.75 price?

Majority of sets I part out is mainly because I buy set since I want 1 or more minifigures from it and then sell the rest....

 

I usually try to part out so I pay less than 5$ per fig that I keep....

 

With Mines of Moria i managed to keep Legolas and Boromir for free after selling the rest of the SET. 

 

But I rarely buy sets on discount to part them then I rather keep them whole and sell later less work

It definitely proves that parting out by auction is not profitable on the LOTR sets.

if you are selling partial sets or whole sets how do you determine your pricing? I'm sure experience comes into it but on a set like your example what helped you pick your $49.75 price?

I look at eBay prices for similar first, both asking prices and sold. At the time I listed the Arkham stuff, there was a sold vehicle for about $40 from the set (fixed price sale). If there are no solds, I look at listed unsolds and generally aim for mid-range high-side (if the average is $10 including shipping, I'll list mine for $12 including shipping.)

Lego is a snap to price compared to books, as there are almost always comparable items to go by.