I have an old Lynx Basic headlamp, as made by Roy Fellows/LED Cap Lamps, which I originally bought in 2016 for around (after deducting the price of a battery and charger) around £60?. No batteries or charger are included so you will need to already have (or buy) a Roy Fellows '8V' battery pack and charger or be able to build your own '8V' (i.e. 2 x 18650 in series) battery pack with an XT60 type connector. It might be a good light for a backup helmet (which is what I used it for) or as a 'project' as it is very easy to open up (the bezel unscrews) and have a play.
Using the power of the 'Wayback Machine', you can view the website back in 2017 when it still described the lamp:https://web.archive.org/web/20180826200003/http://ledcaplamps.com/X_basic.htm
Maximum output listed as 1400 lumens HOWEVER as you can see from the photos the reflectors are damaged; they appear to have corroded somehow and so while the lamp will still put out plenty of light, it won't be as much as it 'ought' to be because of the bad reflectors. That said, I've just tested it and it still puts out plenty of light; I suspect the reflectors can be replaced by the keen.
Starting price: £30?