Firewall insulation retainers

[coffeedart67]

Not sure where this post belongs but since the retainers install from inside the car I put it here. Where should I look for replacement firewall insulation retainers (clips). They look kind of like a plastic nail that is about 1 1/2 long and have a head a bout 1/2 in diameter. They are listed in Year One for $25/set. I hate to pay that much for 6 little pieces of plastic. Checked the help section at auto parts and didn't find anything close enough to work. Not worried about 100% authenticity.
Thanks