I'm going to have to disagree with the above recommendations, ampullaria is not that needy. It may grow in low light, but grows more robustly with better colors in normal Nepenthes med-high light. N. ampullaria will do fine with 60's at night. Not ideal, it won't grow quickly, but it will do fine.
You can very easily and cheaply pick up a small terrarium. If the amp is small enough you can use a 10 gallon fishtank with a glass folding top and a fluorescent light around the 6500k range, available at any pet store and constantly on craigslist. The light will provide much warmer daytime temps as it will put off enough heat if in a more enclosed environment. If you close the glass top at night the humidity will go higher as well. Put in in a higher traffic area of your apartment and keep the top cracked during the day for some air movement. If you use a larger tank, you'll have to invest in a small fan for air exchange. Use something to elevate the pot of the bottom of the tank, ( stones, egg crate, whatever,) and add an inch or so of water to the bottom to help keep the humidity up.
I say this as had an N. ampullaria 'Lime Twist' in this exact situation until it was large enough that I felt safe putting it outside with my other Nepenthes. I used to grow lowlanders exclusively in terrariums until I moved to Florida and N. ampullaria does need humidity, (but even 60-70% is fine if it's consistent,) and warm temps, (but a drop no lower than 60 F at night if conditions stay consistent and it warms up during the day,) it will grow fine and you can keep this species.