Memory Express is a good solution, and even if you can't get price matches they're usually within $10 of NCIX prices. If you can't find the item or they're out of stock at Memory Express, another store to try is BCOM Computers (
BCOM*Computer*Centre). These guys were my first computer store as they were Edmonton first and closer locations, however I've favored Memory Express in recent years (better prices overall / location closer). They use to have more Edmonton stores and a Calgary location but that seems to have changed. Anyways, they still aren't bad for pricing but definitely go for Memory Express first. There are a bunch of smaller shops but don't expect any warranty from them as these shops can disappear from their hole in the wall with little notice.
Be sure to tell your parents that with most prebuilt systems from these shops, you're paying about 50%-75% (depending on where you go) of the cost to parts, the rest for assembly.