I think this is something that annoys many sellers. I have between 5 - 10% of sales result in non payment. I have blocks in place but have noted that very often non payers are buyers with low feedback. The nonsensical system of allowing buyers to create a new ID circumvents the whole process.

As for it not costing money.... For those of us that sell elsewhere we remove that item from sale, so have to effectively relist and readvertise/put it back out for sale elsewhere and not just on ebay. This takes time. Given the average time for payment is 4 days, and the dispute is open for 4 days, there is 8 days lost where the item could have potentially been resold if it were available for sale. For those that have multiple items in stock it may not be such an issue, but for those that sell out of the item, list single items etc, the loss in revenue can be significant. Then there are the relisting fees which are not refunded when the item quantity falls to zero. (Not sure why ebay does not offer a pro rata refund for these?)

I agree forcing buyers to pay is not feasible, and also do not like taking the stance of opening an UID when someone politely asks me to cancel a sale for a legitimate reason. EBay have suggested that this is the appropriate course of action to take, but there is a negative connotation attached to it. I would imagine a good buyer that requests a cancellation and has a dispute opened in response may feel a bit offended. There are of course many situations where an opening an unpaid item dispute is warranted.

I would like to see along with feedback the number of cancellations requested by the buyer (these should not have to be instigated by a seller when it is the buyer that requests it as is the present situation), as well as the number of unpaid item strikes, INR and SNAD claims, negs left for sellers etc. We should not only be able to add members to blocked lists based on the unpaid items strikes, but should also be able to use other criteria to add members to our blocked lists. I am sure there are others that buyers can think of to add with respect to sellers too.