How to Make Items products free after certain purchases?

I want to make certain items free after they make a purchase of a certain amount of $$ spent in the shopping cart. Also, I would like the free item to revert back to its original price if the shopping cart decreases from the minimum amount. How can I do this?

Have you looked into coupons? My server is down temporarily so I can't check it out, but IIRC you can tie using a coupon to a certain product and a certain purchase level, so unless BOTH conditions are met the coupon would be invalid. You'd just set that coupon for the amount of the product, unlimited uses but one use per person (unless you wanted to let them use it more than once) and it should meet your needs. (I'm going to be very embarrassed if I find I'm wrong about what coupons will do when my server comes back up ... but I'll live.)

While coupons would work for this, I find that my customers dont like them much and find them confusing. We would like to do something exactly like the OP wants - have just printed a catalogue and would like to provide that free of charge to anyone who purchases something through our website.

It would be nice if I could just set it up as a product that is $5 (for eg) if that is all they want, or FREE if they buy something else from us in the same order.

Off to do more searching of the forum but if anyone can help, would appreciate it.

cheers
Leah
https://www.aussiesapphire.com.au

The observer/notifier system is ideal for this - in fact the tutorial on the system in the wiki gives a real-world example of exactly this sort of function