Quote from: NothinG on August 11, 2011, 05:46:58 PM

Quote from: Elwar on August 11, 2011, 05:34:36 PM

Well done. It would help to add at the end "Price to sell back at to break even: " eg. 10.12

I wrote the script at 5am.

Give me a few minutes and I'll add that.

[Edit]:
http://gyazo.com/ee34be5c37cce7747d2a1d2316ad3bc2.png
http://zombietoday.com/trade_calculator.php

Code:

echo "What's the minimum price I would have to sell back at to break even?";
if($_GET['volume']>0 && $_GET['ppb']>0 && is_numeric($_GET['volume']) && is_numeric($_GET['ppb']) && $_GET['fee']>0 && is_numeric($_GET['fee']))
{
$volume = $_GET['volume'];
$ppb = $_GET['ppb'];
$fee = $_GET['fee'];
$fee_c = ($fee / 1000); //yea, I know...decided to not use the full percentage
$total_buy = $volume * $ppb;
$min_sell = $total_buy + ($total_buy * $fee_c);
$minMarket_low_sell = ($min_sell / $volume);

echo "[Volume]: ".$volume."";
echo "[Buy]: ".$total_buy."";
echo "[Sell]: ".$min_sell."";
echo "Minimum sell when Price Per Bitcoin is ".$minMarket_low_sell."USD to break even.";

} else {
echo "";
echo "Buy  @ .mtGoxAvg()."'>";
echo "Fee 0.% ";
echo "";
}

function mtGoxAvg()
{
$opts = array(
  'http'=> array(
'method'=>   "GET",
'user_agent'=>    "MozillaXYZ/1.0"));
$context = stream_context_create($opts);
$json = file_get_contents('https://mtgox.com/code/data/ticker.php', false, $context);
$jdec = json_decode($json);
return $jdec->{'ticker'}->{'avg'};
}
?>

Enjoy!

Are you sure the math is right? As stated in Joel's post, a $0.12 spread at $10 is enough to break even. According to yours, a $0.67 spread is required... That can't be right.