Lighed keys are unnecessary and counterproductive.
For some serious piano learning an 88 key with hammer action is essential. Entry level digital pianos made by Yamaha, Kawai, Casio, Roland, Korg are available, but you have to double the budget. A Casio CDP-S100 is the cheapest option at the 360 Euro price and could run on alkaline batteries. Roland FP10, Yamaha P45 and Korg B1 are all around of the 400 euro level.
But for a first run a smaller 61 key keyboard with VELOCITY SENSITIVE KEYS is the minimum baseline. Even with a spring action the speed of the key press will affect the sound volume. Going for a Casio CTK 3500, or a CT-X700 a Yamaha CPT360 or PSR-E360 could be an idea. They have rhythms and nice sounds that could make more interesting the thing.
Another aspect of the lighted keyboard is that doesn't help to get the ear, because instead of associate a sound to a key it associates a light to a key, and anyway music teachers tells that looking at the keyboard it's not a good idea, one has to train the finger to find the correct distance. Actually one of my piano teacher made me practice with a cardboard kiding the keys sometimes. So is important to have standard sized keys.
Sight-reading is paramount to learn to play music especially classical, as with solfege, but lighted keys here are steering in another direction.