Damn... Was hoping they were up for the double cost as they saw armour increase as being 2.8 factor of importance... Is it a slightly random value each time (which would make sense so that people don't just have simple calcs to do to work out exactly what the max is they could sell for each time)
Can I try again? 
Shop 4 sells 27 to 13 for 200...
It's not random, but in the final game you will not see exact values for things like loyalty and needs.
Sold Ring of Protection to Ortel Brim Turok for 200 gold
