[PRICING] Dynamic priceadjustment on textresize

Hello,

Is it possible to adjust the price when changing the size of the text? For someone who needs 1m of vinyl for his text, it have to cost less than if someone needs 2m vinyl for his text. For example, for a car sticker. I've tried the Plus Addon and the Pricing Addon, which doesn't work for both of them. But in Germany (or in the whole EU?) the price has to be stated on the product (always the current one), otherwise you will get warnings. I'm willing to pay for an extra plugin or maybe someone else has another idea.

For example, on this website (http://www.no-refresh.com/demo/lettering/index.php/designertool/) you can change the text size and the price will adjust automatically. But the website is not nice, not responsive and you can't buy the product anywhere.