Ooh very good question @diamondsandrose
Bearing in mind I am not a professional, so based purely on personal point of view.
If you were to buy one gadget only and be committed to using it, I would say the most expensive LED mask your budget could stretch to.
Because it would actually help with wrinkles and fine lines.
I couldn't recommend a particular brand because I haven't looked to buy one yet.
obviously it's not a negligible expense so that is a big consideration, but I can't yet see when I could use it on a regular basis the way my life is at present. Also I am not yet convinced how safe these are for eyes, but only because I haven't read much about their safety. Sometimes it takes me years (1-3 years) to decide investing in an expensive item like this because of safety and because I feel slightly guilty at spending money. And I quite like the anticipation too.
I would look at product descriptions, safety warnings etc on websites such as Space Nk, Current Body, John Lewis, Boots, Foreo. I wouldn't bother with the consumer reviews on these websites but I would choose 3 masks I feel are safest and try and find independent reviews on YouTube. Ignore Instagram reviews because it's all one big advertising platform on there.
I can't tell if any of these masks help with face contours in a meaningful way. The Dior version (insane price) claims to help but I don't know about the other normal versions.
Because this would be of interest to a 49 years old. For along the jawline, neckline, everywhere really.
So if the mask you finally decide to buy does not help with contouring, I think there's a lot to be said for a facial massage you can do yourself when you cleanse your face. Maybe in the morning. Following the movements from the Eve Lom cleansing balm but using a cleanser of your choice, or a facial oil.