Anyone out there use this site for arbitrage?
www.bestbitcoindealers.com, it seems like there are huge differences in price across exchanges. Nice that Exmo actually lets you cash out in Dollars as they always seem to have high prices

There are definitely chances that you are able to get a good deal on your buy order and be able to sell your bitcoins straightaway for a much higher price. But these chances are rare, because there should always be someone before you taking advantage of this opportunity, if it is available.
Where i usually look for arbitrage opportunities isn't the link that you provided, but rather coinmarketcap. You can click into any altcoin that you want to arb with, click on markets, and see the price differences between exchanges.
Those opportunities might look good on paper sometimes but it doesn't work in practice. Why? There may be issues with deposits/withdrawals on the site that is causing the arb opportunity to be there in the first place. You may even lose money if you don't research well before you put in money into these arbitrages.