public function getBid($itemId)
    {
        $item = Item::findOrFail($itemId);

        if (!$item->auction) {
            return redirect($item->url)->withErrors([
                'This item is not an auction, so cannot be bid on.',
            ]);
        }

        $bids = $item->getBidHistory();

        $highest_bid = $bids->first() ?: new Bid();

        if ($bids->isEmpty()) {
            $minimum_bid = $item->startPrice;
        } elseif ($highest_bid->bidder == Auth::user()) {
            $minimum_bid = BidIncrement::getMinimumNextBid($highest_bid->amount);
        } else {
            $minimum_bid = BidIncrement::getMinimumNextBid($item->biddingPrice);
        }

        return view('mustard::item.bid', [
            'item'        => $item,
            'bids'        => $bids,
            'highest_bid' => $highest_bid,
            'minimum_bid' => $minimum_bid,
        ]);
    }