Anit-Tipping Situation. Got burned on a used product, moral dilemna.

[T.J. Combo]

So I got a Wii recently, which is a huge brag imo, I can't stop playing it. Recently I picked up a few good Gamecube titles on the cheap, then found out I needed a Gamecube controller and Memory card.

Now, I was under the impression that my Wal-Mart stopped carrying Game Cube controllers and memory cards, so I checked out this local used games store.

The business is family owned and operated, and I've went in there a couple of times window shopping, he's got some really neat old stuff, but nothing really I'd wanna buy.

He's also a pretty regular customer at Pizza Hut and I deliver to him once-twice a week, and he usually tips a couple bucks.

Today I go in looking for a used Gamecube Memory card, since the last time I was at Wal-Mart, they had none (I got a used Gamecube controller at Gamestop last week, but forgot the Gamecube needed a memory card too. The Gamestop is about 30 minutes away, or I would've gone to it). So he sells me this off brand memory card for $15, and I'm like "Alright, have a good one" and I browse some titles looking for Gamecube RE1 and can't find it, then I head on out.

So our next stop is at Wal-Mart to get some groceries and junk, and they now have the exact same memory card brand new for $10.

So I'm a little like "WTF, why did he sell me a used one for more?" So I'm a little pissy that dude burned me (more the point that he burned me, because $5 is so little).

So I think I might try to return it tomorrow and explain that he burned me. If I do this though, when he orders food, he will probably get just as pissy and stop tipping, which is -EV in the long run.

To date, dude has tipped me more than the card is worth, or what he sold it to me for, and in the last two orders he's made, he's left a $4 tip on a $25ish order, which is pretty big.

Money considered, it's definately -EV to return the card, because he might stop ordering from Pizza Hut, or he might stop tipping when I show up with the order, but there's also that part of me that says: "Hey [censored], you tried to screw me over, you better make it right."

It's a definate dick move to try to return it for purchase price, since I knew what I was getting into when I bought it in the first place, I just thought that major retail stores had quit selling them.

What's your play here? I'm thinking the best that I might be able to get away with is a lie saying my little brother already had one that he gave me and I forgot about it and I'd like to get store credit.

TLR version

I paid $15 for a used memory card when it's $10 for a new one because I thought the major retailers stopped carrying them.
I deliver pizzas for a living and the store owner tips well.
Dude might get pissy if I try to return the card and stop tipping.
I'm pissed that he burned me (more the fact that he burned me than $$$)
Try and return it or just make 3-4 more deliveries and make up the cost of the card?