Royal, Remington, Underwood, LC Smith Corona, Corona, Olympia, Adler, Blickensderfer, etc.
Investment grade typewriters range in price from $350 to the high $600's. Some are much higher. Prices are based on condition, make, model, color, font, scarcity, rarity, warranty (90 day, 2 year or 4 year) and consumer demand. Most available typewriters sell via customer requests before being listed. No need to list it if someone is already in line to buy it.
"SOLD!" means the item is sold and no longer available for purchase. "New" means the item has been recently listed on the site. I receive a lot of emails from prospective buyers wishing to buy sold items and lay away items. I hope this will explain the availability in regard to those items.