We have a Judges Guild subweb here and many of us have done a lot of research of values.
Index by TitleAssuming the condition of the JG items is "Fine", values would be House on Hangmans Hill ($15), Caves and Caverns ($6), Castle Book II (around $10) depending on whether a first or second print.
The Rolemaster books are probably from the 1st Edition Spell Law Boxed Set. A complete boxed set in good condition is worth a bit now, but the three books in the condition you describe, maybe $20 for the three if you are lucky.