I have kids from 14 to 1 year old and honestly the cheapest stuff is the most loved.
My teen has a decent computer (hand me down), a Playstation, a good quality Samsung phone (hand me down from DH when he upgraded) and a Samsung tablet that he has accrued over several years so theres nothing 'expensive' he wants/needs.
While yes they might be expensive if you aren't fortunate enough to be able to source a secondhand one these things are still just 'one time purchases' not things that need regularly updating. I'm always baffled when people quote them on Xmas threads saying they have a 'teen' like they are an ongoing thing everyone buys every single Xmas.
I mean if people are updating to the new Iphone every single year thats frankly a 'keeping up with the Jones' life view and choice. Its a lifestyle I dont encourage in my children and maybe as such is why my kids don't view the world like that and never ask for the latest very overpriced 'brand name' gadget.
The most loved gift is always the noisiest or silliest novelty... from the scream chicken dog toy (which my teen adored) to the pan pipes I regret buying because my youngest 2 constantly fight over its NEVER the 'Samsung smart watch' (that my DS wore once because they aren't allowed at school) or going back the 'wii' (with ALL the accessories that literally got used twice) or the PSP that they forgot we even had etc... thats getting fought over.
Honestly the most expensive stuff usually ends up stuffed in a draw somewhere while the kids are running around trying to KO each out with a poundland football and honestly the tablet is only forced on them to try and stop them when they too hyped up and are going to end up hurting each other and we need them to sit down, chill out and be quiet.