Well I'm late to the party, but I was going to suggest Mini Mark.
Burnham Nursary (down in Devon) sells Mini Mark for arround £25. I think they will be going to Tatton as they do a lot of the shows so maybe they will take some.
I bought one from them back in March and a spike has been growing very fast on it. They said they usually have them in flower, but I was unlucky with my timeing. I don't care because this spike is shooting up.