<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>Document</title>
</head>
<body>
<div>
<select id="tirazh">
<option selected></option>
<option value="1">100шт</option>
<option value="2">200шт</option>
<option value="3">300шт</option>
<option value="4">400шт</option>
<option value="5">500шт</option>
<option value="6">600шт</option>
<option value="7">700шт</option>
<option value="8">800шт</option>
<option value="9">900шт</option>
<option value="10">1000шт</option>
<option value="11">1500шт</option>
<option value="12">2000шт</option>
</select> - Тираж; <br /> <br />
<select id="razmer">
<option selected></option>
<option value="size1">22,5 х 34см</option>
<option value="size2">30 х 40см</option>
<option value="size3">36 х 45см</option>
<option value="size4">38 х 50см</option>
<option value="size5">45 х 50см</option>
<option value="size6">60 х 50см</option>
<option value="size7">70 х 50см</option>
</select> - Размер пакета; <br /> <br />
<select id="cvet">
</select> - Цвет пакета; <br /> <br />
<select id="nanesenie">
<option selected></option>
<option value="1">1 + 0</option>
<option value="2">2 + 0</option>
<option value="3">3 + 0</option>
<option value="4">4 + 0</option>
</select> - Количество цветов нанесения; <br /> <br />
<button>Рассчитать!</button>
<div style="font-weight:bold" id="result"></div>
</div>
<script>
var tirazh = document.querySelector("#tirazh"),
razmer = document.querySelector("#razmer"),
nanesenie = document.querySelector("#nanesenie"),
summ = 0;
document.querySelector("button").onclick=function(){
if (tirazh.value == '1' && razmer.value == 'size1' && nanesenie.value == '1') summ = 500;
else if (tirazh.value == '1' && razmer.value == 'size1' && nanesenie.value == '2') summ = 600;
else if (tirazh.value == '1' && razmer.value == 'size1' && nanesenie.value == '3') summ = 700;
//итд
document.querySelector("#result").textContent = summ;
};
</script>
</body>
</html>