[marvbest]

Just saw this offer for Magnefine filters (5/16", 3/8" or 1/2" sizes) for a pretty good price. For 3 it's $45.45 with USPS priority shipping (from Costa Mesa CA). Since no sales tax (unless you're in CA) so $15.15 each if you get 3 (shipping is $6.25 for 1, $7.95 for 3).

Magnefine 3/8" Inline Magnetic Transmission / PS Filter | eBay

 

[carlsenga]

It looks like the seller is from Magnefine so probably legit. Many retailers seek to post item on eBay for the marketing they get, and the ease of sale process.