I'm a big believer in making buying as easy as possible, and catching the spending impulse... even when it's me buying.
Looked at a few items, then added them to my watch list while I haggled with the seller. When we'd agreed a price I headed for the watch list and it occurred to me it would have been neater if there was a "buy now" button on each item that was still available (and/or "bid now" as appropriate).
It only took a moment to go into the listing and purchase, but as I said at the top - anything that captures that impulse purchase is good.
Thanks.