diff --git a/doc/fixes35.0 b/doc/fixes35.0
index cec8f59a2..fd9801b09 100644
--- a/doc/fixes35.0
+++ b/doc/fixes35.0
@@ -373,6 +373,7 @@ for poly'd hero hiding on ceiling, attack by sea monsters won't move them
 	into hero's position unless it is over water or they're already on land
 for poly'd hero hiding on ceiling, attack by long worm might fill hero's
 	destination with worm's tail, so double check and maybe choose again
+when shop prices are adjusted, handle roundoff (integer truncation) better
 
 
 Platform- and/or Interface-Specific Fixes
diff --git a/src/shk.c b/src/shk.c
index d6992b666..6d423b440 100644
--- a/src/shk.c
+++ b/src/shk.c
@@ -1843,7 +1843,10 @@ get_cost(obj, shkp)
 register struct obj *obj;
 register struct monst *shkp;	/* if angry, impose a surcharge */
 {
-	register long tmp = getprice(obj, FALSE);
+	long tmp = getprice(obj, FALSE),
+	     /* used to perform a single calculation even when multiple
+	        adjustments (unID'd, dunce/tourist, charisma) are made */
+	     multiplier = 1L, divisor = 1L;
 
 	if (!tmp) tmp = 5L;
 	/* shopkeeper may notice if the player isn't very knowledgeable -
@@ -1891,27 +1894,44 @@ register struct monst *shkp;	/* if angry, impose a surcharge */
 			    break;
 		    }
 		    tmp = (long) objects[i].oc_cost;
-		} else if (!(obj->o_id % 4)) /* arbitrarily impose surcharge */
-		    tmp += tmp / 3L;
+		} else if (!(obj->o_id % 4)) {
+		    /* unid'd, arbitrarily impose surcharge: tmp *= 4/3 */
+		    multiplier *= 4L;
+		    divisor *= 3L;
+		}
 	}
-#ifdef TOURIST
-	if ((Role_if(PM_TOURIST) && u.ulevel < (MAXULEV/2))
-	    || (uarmu && !uarm && !uarmc))	/* touristy shirt visible */
-		tmp += tmp / 3L;
-	else
-#endif
 	if (uarmh && uarmh->otyp == DUNCE_CAP)
-		tmp += tmp / 3L;
+		multiplier *= 4L, divisor *= 3L;
+#ifdef TOURIST
+	else if ((Role_if(PM_TOURIST) && u.ulevel < (MAXULEV/2)) ||
+		    (uarmu && !uarm && !uarmc)) /* touristy shirt visible */
+		multiplier *= 4L, divisor *= 3L;
+#endif
+
+	if	(ACURR(A_CHA) > 18)  divisor *= 2L;
+	else if (ACURR(A_CHA) == 18) multiplier *= 2L, divisor *= 3L;
+	else if (ACURR(A_CHA) >= 16) multiplier *= 3L, divisor *= 4L;
+	else if (ACURR(A_CHA) <= 5)  multiplier *= 2L;
+	else if (ACURR(A_CHA) <= 7)  multiplier *= 3L, divisor *= 2L;
+	else if (ACURR(A_CHA) <= 10) multiplier *= 4L, divisor *= 3L;
+
+	/* tmp = (tmp * multiplier) / divisor [with roundoff tweak] */
+	tmp *= multiplier;
+	if (divisor > 1L) {
+	    /* tmp = (((tmp * 10) / divisor) + 5) / 10 */
+	    tmp *= 10L;
+	    tmp /= divisor;
+	    tmp += 5L;
+	    tmp /= 10L;
+	}
 
-	if (ACURR(A_CHA) > 18)		tmp /= 2L;
-	else if (ACURR(A_CHA) > 17)	tmp -= tmp / 3L;
-	else if (ACURR(A_CHA) > 15)	tmp -= tmp / 4L;
-	else if (ACURR(A_CHA) < 6)	tmp *= 2L;
-	else if (ACURR(A_CHA) < 8)	tmp += tmp / 2L;
-	else if (ACURR(A_CHA) < 11)	tmp += tmp / 3L;
 	if (tmp <= 0L) tmp = 1L;
-	else if (obj->oartifact) tmp *= 4L;
-	/* anger surcharge should match rile_shk's */
+	/* the artifact prices in artilist[] are also used as a score bonus;
+	   inflate their shop price here without affecting score calculation */
+	if (obj->oartifact) tmp *= 4L;
+
+	/* anger surcharge should match rile_shk's, so we do it separately
+	   from the multiplier/divisor calculation */
 	if (shkp && ESHK(shkp)->surcharge) tmp += (tmp + 2L) / 3L;
 	return tmp;
 }
@@ -2042,18 +2062,18 @@ set_cost(obj, shkp)
 register struct obj *obj;
 register struct monst *shkp;
 {
-	long tmp = getprice(obj, TRUE) * obj->quan;
+	long tmp = getprice(obj, TRUE) * obj->quan,
+	     multiplier = 1L, divisor = 1L;
 
-#ifdef TOURIST
-	if ((Role_if(PM_TOURIST) && u.ulevel < (MAXULEV/2))
-	    || (uarmu && !uarm && !uarmc))	/* touristy shirt visible */
-		tmp /= 3L;
-	else
-#endif
 	if (uarmh && uarmh->otyp == DUNCE_CAP)
-		tmp /= 3L;
+		divisor *= 3L;
+#ifdef TOURIST
+	else if ((Role_if(PM_TOURIST) && u.ulevel < (MAXULEV/2)) ||
+		    (uarmu && !uarm && !uarmc)) /* touristy shirt visible */
+		divisor *= 3L;
+#endif
 	else
-		tmp /= 2L;
+		divisor *= 2L;
 
 	/* shopkeeper may notice if the player isn't very knowledgeable -
 	   especially when gem prices are concerned */
@@ -2066,8 +2086,23 @@ register struct monst *shkp;
 				tmp = (tmp + 3) * obj->quan;
 			}
 		} else if (tmp > 1L && !rn2(4))
-			tmp -= tmp / 4L;
+			multiplier *= 3L, divisor *= 4L;
 	}
+
+	if (tmp >= 1L) {
+		/* [see get_cost()] */
+		tmp *= multiplier;
+		if (divisor > 1L) {
+		    tmp *= 10L;
+		    tmp /= divisor;
+		    tmp += 5L;
+		    tmp /= 10L;
+		}
+		/* avoid adjusting nonzero to zero */
+		if (tmp < 1L) tmp = 1L;
+	}
+
+	/* (no adjustment for angry shk here) */
 	return tmp;
 }