i wouldn't do it and i wouldn't tell others to do it. for now, concentrate on what you know you need and will definitely use.
each time you make quilt, buy a little extra of the fabric you know you'd like to use again. i wouldn't go buying helter-skelter fabrics that don't co-ordinate or bear any relationship to one another. build your stash based on color preferences or print size or both. don't get sucked into cheap pre-cut deals that don't match anything and have no purpose. as for patterns, use the freebies online and learn from them, before investing $$ on patterns. buy tools only as needed. there's no contest to own stuff.
EDIT: does everyone who says to do it, really do it? not every piece of fabric is the last one on earth. and not every great deal, is even a deal.