Yeah, spigot rings are much cheaper on ebay but you do need to carefully measure the centre bore of the alloy as the size is very precise so you're looking at 10th of mm differences. I've had to sand some down before to get them in the hole!!!
Many sellers will say what alloys the spigot rings will fit anyhow and you can get a full set for less than a tenner, I've seen 'em up for over a fiver each in some wheel places and even then they often have to order them in.