Using Original PENNY5 5% off Sitewide on eBay Deal Post, the Nintendo Switch is $379.05 with Click and Collect on Eb's ebay page. Same price delivered if you have ebayplus.
It has been cheaper in the past but not too often. A pretty good price in any case if you're looking to pick one up.
For another $3.79-ish off the price, dont forget to use cashrewards!