Ripped off for lock rekey?

[Dana Holland]

I had all the exterior locks rekeyed on the house this morning after tenants moved out.  They were very high-maintenance tenants and things did not end on very good terms so I needed to make sure the locks were rekeyed immediately.  I called a company last week who quoted a $29 service call, then between $15-$29 per lock.  I asked what the difference is between the $15 and the $29 as that is a pretty big range.  I was told that the price varies based on the condition of the lock and type of lock.  I figured some locks are conventional and then there are fancier smart locks (which I don't have), or maybe a really old lock would cost more, but it seemed reasonable to expect the cost to be closer to the $15.  This morning when the guy came to change the locks, he looked at my key and said there are 5 points on it, so it is  a more complex and safer type of lock.  He said that a 3 point lock starts at $15, then they add $10 per point, so $35 per lock.  I told him the owner quoted $29 MAX, so he backed down and charged $29 per lock.  I was not happy still and would have called someone else if it weren't for the urgency of getting the job done.  Now I'm looking at places like Home Depot and am finding entire locks for $15-$20!!  I feel like I got ripped off.  Anyone experienced in locksmith services know if the 5 point vs. 3 point locks are really that much more complex and should cost more??  I'm going to talk to the owner and ask for a refund, but would like some facts to present first.  Thanks!