Well, most kits you can get (like at walmart or whatever) don't have the best equipment. My boyfriend bought a 29gal kit at wal-mart and the heater never worked and the filter isn't all that great. So thats another $30+ he has to spend on investing in a better heater and filter.
Find out from your parents how much they are willing to spend. If they are only willing to spend $100, the wal-mart kit is your only option (then maybe later you can replace the parts), if they are willing to spend more than $100 and want you to have good equipment, then don't settle for the wal-mart/premade kits.