I got an ottoman bed from eBay back in 2017 for under £200, just a simple black cloth base.
I went for a side opening one due to the layout of the room, and it comes in two halves with two gas struts for each side. This is the key part to ottoman beds, the front opening ones with a single gas strut on each side are so much easier to accidentally twist and are lifting the weight of the mattress with two gas struts instead of four.
Still going strong and am opening in fairly regularly and is still in perfect condition!