I currently work p/t at WalMart and I also worked in their layaway (we were one of the last stores to get rid of layaway in our area)... one of the big problems we had, was people would put stuff in layaway, pay the minimum they had to, come in just before they had to have it out, .. then cancel the order (or at least the bigger ticket or hard to find items), get their $$ back (as there was no cancellation fee)... wait in the store for us to pull their order and put it back on the shelf (or if we had stock, put the item back in.. one time, there was a person who had 4 of the big kids truck (kinda like the ATV's) .. then they would come back with the same items and put them back in layaway again.. this way they would have a lot longer time to pay it off or in some cases it would down to a clearance price, as when they pay off an item the computer would mark it at it's lowest price..... one time, someone got a $200 some odd dollar order for about $90 because so much had gone on clearance and they were one of the ones putting several of the same orders in during the month (everytime they came in, they would put the same things in layaway)...
we were told things like this was a big decision in dropping the layaway system -- not cost effect...
just people's way of abusing the system for everyone else who used it
that being said, people also said that WalMart's sales would drop because of them taking away layaway and our sales were not lower.... they were even higher last holiday season.. (this is based at least on our stores sales)..