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Another in favour of ebay cheapo remotes here. I get the multi-camera ones pictured below, they are usually in the $2 range. I've never had any issues with them not working*, but I misplace them all the time so I usually aim to have 2 or 3 in my camera bag. As a plus, if you're ever out shooting with someone who uses a different brand, you can loan them a remote. Or just give them a remote, they're cheap enough.
*An exception is when the battery is dying, which causes the remote to work intermittently. Can't fault the remote for that, but given the loooong life of the batteries, it's always a surprise. The batteries are replaceable.