I bought a PC for € 2199 (about $2500 USD) 8 days ago. Today I saw that the same store where I purchased it sells the same product for € 130 less. Unfortunately, I can't just bring it back* and re-buy it because I have already littered the packaging. What can I do in order not to have paid too much?
* The market claims that you can give a product with packaging back without providing a reason.
Two options you can try:
Go to the store and ask them to refund the difference. They might not, but it doesn't hurt to ask. Often stores will do this if you are within the return window because it saves them some hassle over you returning the used item and then buying a new item at the lower price.
Buy the identical item again at the new price, then return it using the old receipt.
I do not recommend any cheating or fraud. Please let me explain further what you might do.
First, attempt #1 above. It is very common for stores to give you a refund shortly after the purchase. Why? Because this is an easier and better option for everyone than any of the other options. The store wants to keep its customers happy; that is why it has the generous return policy in the first place.
If the store employee doesn't go for this, (perhaps he doesn't know how to properly enter this into the register), tell him that you would like to buy the item today at the new price and return it at the old price with your old receipt. This may not have occurred to the employee as an option, and it might help the employee figure out how to enter this transaction and give you your refund.
If the store employee doesn't like this, tell him that you are planning on purchasing the new item today and returning the old item tomorrow. At this point, the store employee might realize that the store is better off keeping their new item on the shelf than they are exchanging a new item for a used item, and allow you to do the second option right there.
It's possible that they won't go for this either. Now, if you purchase the new item, you'll have a decision to make. You need to return one of the items with packaging using one of the receipts.
If the store is logging serial numbers on the receipt, it may not be an option to return the new item with the old receipt. If the receipt does not contain the serial number, I would argue that there is no fraud or cheating going on by returning the new item with the old receipt. If the receipt does contain the serial number but the packaging does not, then you should be able to use the new packaging to return the old item.
Depending on how you paid for the item, some credit cards have price protection insurance.
There are always minimums (e.g. Must be more than 10% or €150 whichever is greater) and paperwork, and processing time, but it does not involve the retailer agreeing to your request.
Ultimately this is just bad luck. Prices change, especially for things like computers which become obsolete in a short time. At the end of the day a cutting edge PC is only cutting edge for about 6 months and will be old hat in 2 years, so there is bound to be some point where the price drops. After all, putting things on sale at the end of a season is pretty standard practice in retail.
Ethically your best bet is to go to the store and explain your position, they may offer you a goodwill gesture but they haven't really behaved unreasonably. If I was the store manager I might be tempted to offer you an extended warranty or offer a discount voucher for peripherals as a goodwill gesture but I wouldn't; expect anything with real tangible value.
As mentioned in comments, if you thought it was a fair price when you bought it you haven't really lost anything.
In the US, you must rely on seller policies and manufacturer guarantees [citation needed]. In Europe, you additionally have certain buyer's rights which are very significant and virtually always preferred over the former.
Since this is in Europe, let us first make a distinction between buying offline at a physical store, and remotely (e.g. online or via telephone).
In the offline case, you have to rely on store policy. If they offer returns, you can try and ask them nicely. Since stores compete with online merchants, it's likely they'll go the extra mile and let you return it or offer the price difference in cash or store credit to make you a happy and loyal offline customer.
On the other hand, if you bought it remotely, there are pretty customer-friendly regulations in place. You're allowed to return such an item bought for any reason within 14 days, paying only the return shipping costs (not for the initial shipping!). That is, minus a usage fee, if (and only if) the item lost value greater than its packaging cost, e.g. if you scratched it, and does not always apply to digital or digitalizable goods, and never to organic or similar goods. Of course, sellers will be glad to refund price differences to avoid returns. That customer-friendly law is also a reason why prices here are generally a bit higher :)
If the item were damaged or faulty at the time of purchase (not later!), they must accept its return (after repairing it up to two times, if they chose so) under general warranty in the EU, regardless if you bought it on- or offline. This topic is a bit complex in itself, with a 0.5 and a 2 year time period of importance, but I won't go into it as it is not applicable to your case.
Some retailers like Amazon will give you back the price difference if you are within the return window of the product. I've done this a couple of times and there seems to be no issue about it - they pretty much prefer giving you back a few dollars than having the product returned used.
You should just ask the retailer for the refund of the difference.
