Eat ~100mg of caffeine really quickly (like a caffeine pill or slamming some coffee maybe) and immediately set a 20 min to 45 min timer and get into bed. Fall asleep and depending on your condition you will feel mildly to very refreshed after you wake up. You'll probably be up even before your timer goes off if it's on the longer side.
Modafinil is way more expensive than caffeine. So if you are going to get addicted to one the latter is better. You can probably buy a 2 pound bag of chinise restaurant tea for 30 usd thats about 1000 cuups of tea. While modafinil is what 14 tablets for the same price?
I took Modafinil for a couple years, never developed a physical dependency on it, while I get nasty headaches if I don't get caffeine. It'd be like $0.25 for a day's moda.
Thats a lot cheaper than what i get them for. There is no reason not to indulge then.