Repotting Question and Lighting Question

Ok I have a couple plants that are 3 weeks old. They are in standard size red solo cups! At what point do I transplant them to thier final pots? I have just begun giving small nute dosages in water every 2 to 3 days. I want to make sure they are good and ready before transplant. They look rather small. Pic one is 1 week old and the other is now at three weeks. Also I still cannot afford decent lighting, but want my plants to veg well and grow. Can you give me some alternative to hps and mh? I was thinking better CFL's bigger, with more wattage? I have seen big clip on light fixtures (silver) and am thinking of maybe a combo of a vegging and flowering compact florescents. I cant really afford a ballast and hps now, but feel my four 100 watt CFL's are going to fall short in a bit, and want to be ready. Tell me the best lights to get and where on a budget of say $50-75. Also I have another transplanting question. I have heard it is best to transplant in the same soil mix the plants started in. However I have some Miracle Grow stuff that has nutrients in there that might be beneficial. But I have heard bad stuff and good about miracle grow. I know the plants will be established, and may be able to handle and benefit from the added nutrients, plus those I water in. Your thoughts on Miracle Grow potting soil? My other option would be my mix of Scotts potting soil, perlite, and a little sand for drainage, that they have started in.

they look pretty small to be giving any nutes yet and as for tha lights get a shit load of cfls untill u can afford wut u want and transplant them wen u see there roots sticking out (wrapping) around the drainage holes