Challenge - Registered users enter values in DB

In the process of making a production site I need to have users enter values in the DB.

- - - - - ENTERING VALUES IN DB - - - - -
These values should be linked like this;
Type_of_product product_model salesprice quantity store week_no

The info must be placed on one row, so it is easily distinguishable which price goes with with which product and which week... This means that I need to group the above fieldsets per row.

The form must be dynamic so the number of recorded products may be increased untill all items is entered (Unlimited no of fields). Then the users should be able to save the content to the DB.

Is there any module out there other than 'Recipe Module that links values like this in one row in the form when values are entered? Or how do I use CCK to do this? If I try this with the 'Recipe module' I have no access to the fields of 'Recipe module'. Hence I cannot use the fields in Views, which limits my use.

I don't know how to place these fields in a row and link them like i need to... Any hints? The new Combogroups functionality for CCK sounds like it will do the trick (but this is only in early development as I understand it). Any thoughts on this.

- - - - COMPUTED FIELD - - - - -
A computed field should then compute:
- In which product_types there have been new prices entered for the week
- From these new prices in every product_type;
- compute the 3rd lowest price and store as 3rd_lowest_price and link to week_no
- compute the 2nd lowest price and store as 2nd_lowest_price and link to week_no
- compute the lowest price and store as lowest_price and link to week_no

Is there anyone who can give me some input to the PHP needed for the computed field above?

Any and all help is much appreciated.

I'm a newbie with some admin experience with PostNuke 6 years back. So I have not done much coding myself, but am willing to learn to get the needed functionality.

Thanks a bunch guys & gals

Morten