Selling Products By Weight: Multiple Options & Accurate Stock Management

Question

I'm fairly new to Magento - I have no idea how to achieve what I am about to propose, nor what would be the best way to go about it.

(Note: This is not a question about the Weight attribute)

My store sells a number of products that I buy in bulk and weigh out into smaller amounts for sale to retail customers. I already sell these products in smaller and larger packs - eg 25g, 50g, 100g, 250g - these are currently set up as simple products and arranged into categories by type of product.

Eg Category: Herbs/Sage contains "Sage 25g", "Sage 50g", "Sage 100g", "Sage 250g".

This is obviously terrible. Apart from populating each category with near identical products with identical images and descriptions, it also makes stock management a nightmare: to ensure I don't sell more than what I have, I have to split up a wholesale order of, say, 5kg into 4x250g,10x100g,etc,etc. This brings up the issue that it's now possible to have 250g in stock, but not 25g if all the preallocated 25g bags have been sold.

I would like to have situation where buying any one of these products takes a total stock down by an amount representative of the size of the product.

Question 1) Is it possible to use "bundled products" for this?

I imagine something like this might work. The product with the lowest weight (25g) is a simple product - when I get, for example, 1kg more of that product from a supplier, I can then set the stock of the 25g simple product to 40 (40 * 25g = 1kg = all my stock). Then I would create bundled products containing multiples of the simple products. Eg my 100g product would be a bundle of four 25g simple products. Then, when someone purchases a larger quantity, the stock of the simple product is reduced by the correct amount. (100g product = 4 * 25g simple product, buying the 100g "bundle" reduces simple product's stock by 4)

Is this how bundled products work?

Question 2) Can I group these bundled products up into a single configurable product?

Now that accurate stock management has been taken care of above, I would like to get rid of the multiple nearly-identical products by combining all the available weights into one (I assume) configurable product. This way, only a single product appears on the site, with one image, one description, one url, etc. I could then get rid of the bottom layer of my category hierarchy, so then my single "Sage" product would sit in the top-level "Herbs" category.

Question 3) Of course, being new to Magento, I have no idea what I'm talking about. Is there a better way to achieve everything talked about above?

(I don't actually sell herbs, this is just an example)

Answer 1

Not sure if this fits your needs but here goes:
Like you said set the actual product will be the one with the lowest weight. (Sage 25g). This is qty = 1(or you can consider 1 qty = 1g and set the product to be available for order only in increments of 25.) If the price for 50g = 2 * price of 25g , the price for is 100g = 4 * price of 25g... and so on, then I think the problem is solved. Selling 50g is the same as selling 2*25g even if you pack it differently.
If price for 50g != 2 * price of 25g, then you can use the tier prices.
Set a base price for 25g (or 1g if you considet 1qty = 1g). Then add the tier prices: for qty = 2 (or 50) price = X for qty = 3 (or 75) price = Y.

In this approach you don't need bundle or configurable products.

Answer 2

Building on Marius' answer, Qty would be desirable to manage your stock because Qty is not a defined unit of measure in Magento. Qty can be anything - a yard of fabric (length) or a pound of coffee (weight). You can even sell fractional quantities of items in Magento, and you can enforce quantity increments in your sales as well (e.g. you could stock 10.2 lbs of coffee, but sell in .25 lb increments). It also has the added benefit for Wholesale orders - generate those from your admin backend and you can apply custom quantities and prices at-will.

Optionally, I know that on the surface it sounds undesirable, but if you have limited quantities of each item at each weight (e.g. prepackaged, not made-to-order), then you should consider the use of configurable products: set up a simple product for each product at a differing weight, and associate those to their configurable parent.

Answer 3

Yes, you can easily create configurable product, and then, simple product from it. But you won't be able to manage the inventory for your product. Attributes used for configurable product seems to be use for product that are not the same as each other. For example, color, size, etc. You will have a distinct inventory for each of those product. But for your "weight" product, it shares the same inventory. I have right now this problem, and looking for a way to resolve this.

Answer 4

I have searched a solution for this problem and I think I just found one. There seems to be an extension called Product Units and Quantities and that seems to solve at least our problem:

http://www.aitoc.com/en/magentomods_units_and_quantities.html

With it you can make predefined qty selections as drop-down menu so you can allow customers to order for example 25kg or 50kg of certain product and the amount is then deducted from the stock qty of the product.

Only fallback is that it does not seem to support decimals so you can't have a selection for let's say 0,75kg.

Answer 5

The problem with this extension is that I cannot price the various units at different prices. It still boils down to the increments are pre-set, and do not deduct from some master product. They are all simple products - and I am limited by being required to offer the same price no matter what increment. I might offer better rates for bulk purchases..but it's not clear that this is offered.