I have always used Coinbase to buy Ethereum and Bitcoin. Recently I noticed that Coinbase has a lower value of Ethereum than the likes of Coinmarketcap and other cryptocurrency measurers. An example is today (6/7/17) at 2:38 PM, Ether was trading at $234 on Coinbase, but on Coinmarketcap it showed $244.
$10 might not be such a big difference but when a person is buying say 100 Ether thats $1000 of difference!
I don't know how both trackers decide on their price but if you dig deeper, when Ether was trading at an all time high $411 
Coinbase said it never reached the $400 mark!
If anyone in the community can explain to us why Coinbase devaluates its Ether price, we would be very appreciated it!
Menajem Benchimol- concerned Ether buyer.
In the end, their fees kind of bring the price back up to the full market price, but yeah, buying Eth through coinbase is a consistent way of getting discounted Eth. Taking this even further, there are some people who use the different prices at exchanges to trade coins back and forth, making a profit via arbitrage. There is nothing to be concerned about, unless you don't like getting an instant profit.
I was concerned about selling it lol, but thanks for the insight!
Can you tell me other places one can buy and sell ethereum and exchange it back to USD?
Taken from https://cryptocurrency.market/faq/, although I personally have only used coinbase.com. I suggest you check out the rest of their website and their youtube channel "https://www.youtube.com/user/PrisonOrFreedom/about".
♦ www.Coinbase.com
♦ www.GDAX.com
♦ www.Gemini.com
♦ www.CumberlandMining.com (For block trades >$100,000 USD)
♦ www.Kraken.com
♦ www.TradeBlock.com (We use the aggregate BTC price for our block trades)
Coinbase's prices are always slightly inflated since they are one of the few popular ways for Americans to convert fiat to crypto.
From coinmarketcap.com's FAQ:
Thanks mate for the info!
No problem :)
All of the coins vary significantly in price at different venues.
Keep in mind that Coinbase isn't a real exchange. They buy coins (probably from Bitstamp) and sell them with a smallish markup. So if Ethereum is cheaper on Bitstamp than Bittrex, that is the price difference.
Coinbase surely does some trade internalizing also: someone sells 10 ETH on the platform and you want to buy 5. They then match you with the 5 and match other people with the remaining 5. Of course, they will make their money on the spread.
Why are there such big differences in the prices of coins amongst the different exchanges? It is a funding problem. It is somewhat difficult to get fiat into crypto in most countries. If it was easy and also moving funds to different venues was instantaneous, then there wouldn't be any significant price differences. Algos would instantly arb out the price differences.
Every time something major goes on, all coinbase services stop. Coincidence, manipulation, chance?? You decide. It is majorly fucking inconvenient to lose access to your wallet and dashboard. Four times in the last month.
I am guessing little by little they will fix and upgrade their service. I feel you man. Try using other wallets such as polienex or bttrex?