Hoi - Apple's EOL policy is difficult to predict from the outside, but so far quite "long-lived" and long-lasting.
The iPhone SE - depending on the generation - was actually discontinued in 2018.
But if it's like my 6s (which I have as a backup phone), which was discontinued in 2016, and where I still get updates for it - just not all the functions, then the SE could still be supported for another two or three years, but then it might not get all the function updates either (because it might not be possible any more in terms of platform or performance).
Only you can decide what is worthwhile:
- Do you want an iPhone without much AI, lenses, 5G and pay 508.-- for it?
- Do you want an iPhone with a bit more features, camera, 5G for a bit more (Apple iPhone 12 mini (128 GB, Black, 5.40 ", SIM + eSIM, 12 Mpx, 5G))?
...or just the FullMonty
Apple iPhone 13 (128 GB, Midnight, 6.10 ", SIM + eSIM, 12 Mpx, 5G)
or just twice as much as the SE: Apple iPhone 13 Pro (256 GB, Graphite, 6.10 ", SIM + eSIM, 12 Mpx, 5G)

The newer the generation, the "longer" it's supported.... the higher the price, the more "features" ;)
Or just: Second-hand here or from an iPhone second-hand supplier...

Hope I didn't run you over, wish you happy holidays and LG