Used lower value priority bins first.

SawCut/MultiBin.cs

@@ -6,6 +6,9 @@
 
         public double Length { get; set; }
 
-        public int Priority { get; set; }
+        /// <summary>
+        /// Lower value priority with be used first. Default to 25
+        /// </summary>
+        public int Priority { get; set; } = 25;
     }
 }

SawCut/Nesting/MultiBinEngine.cs

@@ -13,7 +13,7 @@ namespace SawCut.Nesting
         {
             var bins = Bins
                 .Where(b => b.Length > 0)
-                .OrderByDescending(b => b.Priority)
+                .OrderBy(b => b.Priority)
                 .ThenBy(b => b.Length)
                 .ToList();