those are the exact ones i am using, i bought mine for 29US each.
go to customaquatics.com and find the product for $29
http://www.customaquatic.com/estore/...=LT-VAPRDE-L10
then email aquacave.com and ask them to price match it.
http://www.aquacave.com/250w-metal-h...lens-1537.html
aquacave shipped 3 to me for $34US