eBay

Yes, you can change it every 30 days

Well, its better because the things that they sell on eBay are cheaper, but at the same time its not good because a lot of the things they sell there are used, broken, and dirty. eBay is a site where people that have things they don't want like t-shirts, toys, instruments, and etc. sell all that stuff.

To promoting their marketing strategies

Yes.

it depends what kind of post the outher person put on the packaging like first class , next day delivery , second class but it should have said when it should be arriving

Never send cash through the mail. Use a trusted third-party source for payments on websites like ebay. NEVER give the seller your personal / banking / credit card information.

Firstly, check the item listing to see what the seller says about accepting returns; some will accept returns for any reason, some will not. If you need to return the item because it is broken or "significantly not as described" and the seller refuses to help you, you can contact eBay and ask them to help you resolve the problem.

15 hours

You lose that round. In the game of Rook, your bid is an estimate of how many points you expect to win through the tricks you expect to win. Your opponent's job is to take as many point cards as they can so that you don't meet your bid. They don't need to win more tricks or take more points, they just need to keep you from making your bid.

Payment options depend on the specific seller. Read the item listing for payment details.

sometimes gun stores will buy them of you

Yes but the user has not bought or sold anything according to Ebay.

Yes, you are allowed to do that.

Yes it is

This depends on what store your shopping at online. Some stores, don't let you use your gift cards online, some are in store use only. Check with your store for details, pertaining to gift cards.

No, you aren't obliged to inform the buyer that you have dispatched their item but it is good manners to do so.

Letting your buyer know that their item has been shipped will also help to give them some idea of when they can expect the package to arrive.

No, depreciations are not directly included in the calculation of GDP. GDP measures the total value of goods and services produced in an economy within a specific period, using either the production, income, or expenditure approach. However, when calculating Gross National Product (GNP) or Net National Product (NNP), depreciation is accounted for by subtracting it from the gross figures to reflect the net value after accounting for capital consumption.

you can open a case on eBay and if you are telling the truth you should win the case and get your money back plus leave the seller a very very very bad feedback

Watchers mean nothing at all so it doesn't matter how may you have.

Sometimes you will have lots of watchers and your item will go unsold because not one of them will bid. Other times your item will sell for a good price and you will have had not even a single watcher.

2 days

Ebay runs a website, where registered users can buy and sell stuff - that's what Ebay does.

To list an item cost you about .35 cents. When you sell it you pay final value fees. The final value fees are a complicated percentage of sale. Pretty much if you sell something for $50 you should expect to pay about $5 to sell it.

5-7 days plus handling time