I've been playing the keyboard on and off for about 8 years now, I haven't really invested in a keyboard, but I try to get ones that that are all-in-one at a good price, so I think I can help
I would recommend Yamaha PSR keyboards
They tend to have a very wide range of synths and others sounds
I have a PSR-170 from 2001 that I got used for 30 bucks
It was my first, and is still my favorite
It has MIDI and all that jazz, output too
Built in metronome
Teaches you how to play, no light up keys, but a solution would be to get stickers to put on the keys that show you what note it is
Haven't played it in almost a year since it's at a relatives at the moment, but I know for a fact there's quite a bit of synth sounds and lots of effects, which are why I like the PSR line so much
Got a PSR-E363 in December last year for $200, more modern synth modes, but will still most likely work for you
Plugged in, it does have some static in the background, unlike the 170, but the E363 sounds more realistic, like a real organ or piano
Also has built in lessons, but still no light up keys
I did see a Yamaha with light up keys in a music store a while back, I think it was a model from the early to mid 90's. It was pretty beat up, so if you really want one with light up keys, it might take a bit of time to find one that hasn't been left in the rain at a yard sale (Seen it happen to a poor PSR, R.I.P buddy...) and thoroughly curbstomped
In conclusion, I'd say the PSR-170 is great if you want more 'fun' synths or electronic sounding ones
and the PSR-E363 if you mostly want a clean sounding piano and modern synths, compared to more 90's sounding synths
I'd have to say, I think the PSR-170 is better and more fun to play around with and to make music with, but it's all up to the person playing it, so before taking my word, do some research on both of them, and decide which one will work best for you
Hope this helps you, and I wish you luck
-Tim