I would check the other relevant tgread as it had warnings about places that are not good for female travelers
https://www.dcurbanmom.com/jforum/posts/list/1248085.page
That’s a big ask for such a budget - yiu may need to look at southern and Eastern Europe.
Italy might be hard on that budget but may be possible. We loved Nerano/Amalfi Coast in Italy (closest airport Naples and then take regional train to Sorento then taxi along the winding steep coast). Locals are super friendly, great seafood and There are many airBNBs in the area - maybe if you split airNnB costs you can make it work.
10 Fabulous Cities In Europe For A Girls’ Getaway
https://www.trailingpages.com/fabulous-cities-in-europe-for-a-girls-getaway/
Budapest, Hungary
If you are hoping to book a trip to one of the cheaper cities in Europe, then look no further than the beautiful city of Budapest. Home to gorgeous architecture like the Fisherman’s Bastion and world-famous thermal spas, its hard not to love about this Hungarian capital and relaxed vibe.
Besides its affordability and lovely tourist attractions, Budapest is also incredibly safe and often lists as one the best places for solo travelling – so be assured that you and your girlfriends will feel right at home.