price per weight / stock control

Hi,

I am struggling in setting up the prices for my teastore.

I am selling loose tea and it should of course be sold by grams, i.e. 20g, 50g, 100g, 200g etc.

I can set this up with the options but herein lies the problem
Setting up the different options per gram (as above) I would need to give a quantity for each option I want to sell.

That is impossible to do.

If I buy let's say 2 kg of one variety of tea I do not know how many different options I would be able to sell. So I cannot say, I will sell amount x of 20 g, or amount x of 100g etc.

So what i am looking for is an extension with which the customer in the front end can choose the weight.
And that this weight is deducted from the basis quantity which is in stock.
So, if the basis quantity is e.g. 2 kg it then should be deducted with the amount put in from customers in the frontend.

Does that make sense?

If anyone could help, that would be great.

I have been searching for something similar like that since weeks. And it seems that I am not the only one in need for that. however, nobody has come forward with a solution over the last years which to me seems to be quite weird.

I am really desperate for a solution!

Regards
Sabine

nobody?