Hello Brett,
You have an extremely good point about the cost of the Enya No3 plugs. They make me wince eveytime I have to buy some! The upside is they seem to last much longer than most, in my applications. I did try the Thunderbolt plugs, but I didn't have a happy time with them. That was some while ago and maybe it is worth another try. Before I went to the Enya plugs I used some made by Dennis Allen (he of AM and Merco fame). I think they were called Firepower, I have not seen any in a good while, pity because they were both good quality and relatively cheap.
Regards,
Andrew.