Be not afraid of buying used (but not abused) equipment....
Everything I own, with the exception of 3 pieces of 'pro audio' is used.
Starting 'small' is nothing to be embarrassed about.....but being 'picky' about What and within budget basically (imho) resides in your choice of speakers.
Like us, they have distinctive 'voices', and traits within that....That will take the bulk of your time to find what you like....
The majority of 'upstream' equipment has decent and acceptable specs and response. It's only when one has developed personal preferences as to how it responds to the music you like that the more minutia become relevant and important to your enjoyment.
Buy the best you can rationalize for what you've in mind for your ears.
Pay attention to the space that will reside in.
'Bright' speakers in a 'live' room can be a bit much, as will the inverse of that.... One way to consider it is to approach the endeavor as a balancing act.
Don't be afraid to invoke the SAF option (if available *G*); they do tend to have an edge of sorts, and they generally have to live with the system as well.
The KISS factor is important. She may want to use it as well. It shouldn't require a Phd to play a CD or even an LP....
My SigOther learned how to use a destat gun, a fibre brush, and a cuing lever. It's not rocket science, just good technique....;)
Go forth and enjoy the journey. *S*