Just use Vapecrawler, then put in the item you are interested in buying, then you will see the prices listed.
Discount codes are listed on the site here under COUPONS at top.
best way to know about discount codes, which often change or there are specials, is to be LOYAL to a few vendors, sign up for their newsletters, and you will get them in your email when they happen.
YOu can also check the deals and steals topic here on ECF.
Deals and Steals