Visiting Kiev for the first time!

Not safe. 

1.   Cheap good hotels are around 80-120 USD.   Better ones are 250 and up.  Just look it up on hotels.com or something like that.

2.   If the girl you are meeting doesn't offer you a guide through her agency, you're doing okay.  If they do, chances are high that she's just a woman working to make money on peeps like you.    As for price,  think 20-30 USD a day.  That should be plenty but since you are a foreigner, you'll be gouged unless you know someone.

3.  You are poop outta luck for the most part.  There are a serious number of scammers out there.   Don't come here thinking that you're going to marry that girl.  If she starts asking for transportation money (taxi money) to get back to her village, then your odds are really bad.    No decent Ukrainian woman will ask for money.  And those decent ones are never model looking with mile long legs and huge breasts.   And no they don't look like Ani Lorak of 10 years ago. 

Chances are very high that the girl is a figment of your imagination.  Sorry to be blunt but there are too many scammers.   

I really hope all goes to your expectations.   If it doesn't thank me later by giving me a thumbs up.  LOL

To each their own.  There are a lot of scammers.  There are also some very good women in Ukraine.  The problem is finding one.  I live in Kharkiv with my family.  I was one of the lucky ones.  I found my lovely wife a long time ago and we have been together ever since.

I wish you luck.  Just keep your money close at hand and hidden.