What she said. I was too cheap to buy the reproductions on eBay when I had my last pair of L100s. Today, I would do it in a heartbeat, because:
(1) Clean L100s are worth a lot of money these days; $600+ easily. Compared to that value, the reproduction foam grills are a very reasonable investment.
(2) They look so good with the new grills, and their looks is a very important part of that model, in my opinion.
(3) The grills boost their resale value.
(4) Who knows how much longer they will be production? Once they're gone, they may be gone forever.
(5) Did I mention how good they look?