I have bought new Crydom's for less than $10. If you are patient, you can get great deals on Ebay. Surplus, old stock, etc. I bought some for spares that looked about 20 years old but were still "new in the box". I have never used them because I have never had one go bad. When you think about it, these industrial components are made for 24/7 use - I use mine for 6-8 hours a month. I will likely croak before my SSRs...