Perhaps you would accomplish this with something to the effect of

text = raw_input("please give 2 numbers to multiply separated with a comma:")
split_text = text.split(',')
a = int(split_text[0])
b = int(split_text[1])
# The last three lines could be written: a, b = map(int, text.split(','))
# but you may find the code I used a bit easier to understand for now.

if b > 0:
    num_times = b
else:
    num_times = -b

total = 0
# While loops with counters basically should not be used, so I replaced the loop 
# with a for loop. Using a while loop at all is rare.
for i in xrange(num_times):
    total += a 
    # We do this a times, giving us total == a * abs(b)

if b < 0:
    # If b is negative, adjust the total to reflect this.
    total = -total

print total

or maybe

a * b

Using a while/else loop produces your desired behaviour.

• The code in the else doesn't run if the break in the while loop is encountered

Code

price= int(input("Enter the price: "))

price_list=[]

while price!= 0:
    price_list.append(price)
    if price< 0:
       print("Wrong entry")
       break
    price=int(input())

    price_sum= sum(price_list)
else:
    print(f"Avg price is: {price_sum / len(price_list)}")