To speak figuratively, the two of you aren't just from different planets, but different galaxies.
If you really want to stay with her, you need to have an honest discussion about what kind of boyfriend you are willing to be, and that will include specifically telling her that you are already aware of enough key differences to realize the two of you will never live together or get married (e.g., wanting v. not wanting kids - that is a long term deal breaker. Always). Also tell her that you are not the kind of guy who thinks $1600 purses are worth the money and would never buy one (personally, I'd be upset if my husband bought me one - I can think of soooo many things I'd rather spend $1600 on!). Don't become one just because you think that is what she wants; she has played it way too coy and you could be out of both the money and the girl, so forget it, don't engage and don't try. Make it clear that despite her romantic notions of how you should just "know" what she wants, you do not and never will, and don't want to play the game of trying to read into her statements and signals, as that detracts from the quality of the time you spend together. If she wants something, she will have to ask, and you will get to say yes or no. That doesn't mean you can't ever surprise her, but keep it to small things, like her favorite tea when she has cramps, or a single rose when she has had a bad day. Then MAYBE, after you've been together for a year, you can splurge $500 on a nice piece of jewelry for Christmas or Valentine's day.
Basically, you are the kind of guy who needs the up-front type of relationship my husband and I have. Women who want the same actually do exist, and you will find your relationship feels much, much less complicated when you are with someone who more closely aligns with your view on relationships to start with.
Tell her you think she is attractive and you enjoy spending time with her, but these conflicts confuse you and that, combined with the clear difference about wanting kids someday, makes you question if it is fair to either of you to continue dating. Tell her if she can accept you as you are you do enjoy her company and want to date, at least for the short term, but there will come a time when she will have to end it to pursue a relationship with someone who wants kids. Throw it into her court. And then accept whatever she answers.
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Mom to an amazing young adult AS son, plus an also amazing non-AS daughter. Most likely part of the "Broader Autism Phenotype" (some traits).