Lights cost around 22€/ea and I bought 2(for 2 plants), 84 true watts. Neutral white spectrum(4000K) light emits good amount of blue photons(I think around 30%), that encourages cell expansion, which is essential for autoflowers. Oxygen in soil is also very important. I made soil as airy as I could and the pot I used have lots of holes on the bottom; potencially draws air through soil, more oxygen for roots. The only problem I had was heat(closet grow ofc) but afterall, came out very nice for money invested.
-2x lights (2x22€)
-cheapest fan(15€)
-soil 25L(6€)
-1x seed(13€)
-terra bloom(10€)
-pot(had one at home)
-electric bill(not much tbh, 15-20€ max, within 2months - 24/0 from start to finish)