All of these are correct.
1. Although it was expensive, she bought it.
2. The purse was frightfully expensive. She bought it, however, because she had no choice.
3. Though it was most attractive, in the end she couldn't buy it.
4. Although she bought it, in the end she returned it to the shop.
5. However many times she shopped there, she never bought a thing.
6. However expensive it may be, she fully intends to buy it.
7. Although he fully intended to pay for the merchandise, he forgot, and was promptly arrested.