Dimity, what a fun time you'll have ahead of you revitalizing your style! When I joined YLF I was in a similar position to your former one -- I had virtually no budget for clothing and had to make do with thrifting and consignment. (Except for undies...agreed!) Then I got a full time job and had a few years of wardrobe building. Now I am about to leave that job and will be curtailing my full-price purchasing again.
Based on my own experience (not always what I did, but what I wish I did!), I would say the following:
1. Haircut is first priority. Remember that if it will also require regular upkeep and make that part of the budget.
2. Footwear for SURE. It can update an outfit like nothing else and will earn its keep providing you buy the right styles. My goals for myself in that regard are:
- comfort (I walk a lot)
- must be a very current style at time of purchase so I can happily wear it for several seasons
- think about how each shoe/boot will work with actual outfits. Will it add figure enhancing qualities (like extending the leg line)? Will it harmonize with bag, coats, etc. How does it add value to your wardrobe?
I do buy my shoes gradually and I pay close attention to Angie's recommendations. Try on different brands to figure out how they fit, even if you are not ready to buy.
A good rule of thumb is at least one dressy, one mid-range, and one casual per season. If you have budget for more, I always love to have one dark neutral in my key style (for me, booties, since my dominant season is winter); one lighter neutral; and one colour. A print is also great!!
The items you've selected look great if your lifestyle is fairly casual and you live in a cool climate. I actually have the merino turtleneck from Gap and like it. It's a tiny bit scratchy in comparison to some J. Crew merino knits I have, but acceptable, and a nice weight. I can also vouch for Kut jeans; I don't have that style but do have others and they are great quality for the price and really wear well.
I'm a huge lover of tote bags for commuting, too, and they definitely add something to the outfit. I also recently tried an upscale backpack and really enjoy it!
Good luck with this new phase of wardrobe building!