Nevo you're outta luck ... i couldnt find fin plugs for cheap anywhere ... or definitely not anywhere reputable. I'm happy to give a cheap set of fins a go, but i would be hesitant to put a sub-standard set of plugs in, cos it'd be a bugger to drill them out and put new ones in if they cracked.
I've just done a board using the shapers s-plugs, seem pretty good, I reckon I'll use them for the next ones if I don't really splash out and get FCS II plugs. Which in Aus you can only seem to get from surfboardstudio.com.au @$60 for a 5 fin set ouch! I've also used the old fcs plugs from shapers.com.au, no problems and they're about the cheapest I could find.
Consider talking to the dude at
[email protected], he will do a good deal if you're buying 3 sets at once