LIp Augmentation is an art and not a science. There are certain fillers which will make your lips fuller such as Juvederm and certain fillers which are designed for finer areas such as Belotero or Restylane Silk. I would begin with a single syringe of product which is in your budget. I would consult a dermatologist who has cosmetic injection experience for the best cosmetic results to match the desired result with the best product for you.
Lip augmentation can be performed with a hyaluronic acid filler. It may take more than one syringe for you and therefore may require more money than you're willing to spend. Best of luck.
the only way to really have a permanent lip augmentation is to put in a lip implant or do fat transfer from a liposuction procedure. you can do silicone injections as well which is semi permanent but you do need to touch up. you may want to consult your doctor
Restylane Silk is a wonderful filler new to the US market that is designed to enhance the lips without creating an overly filled un-natural look. You already have reasonable volume to your lips. Only one syringe of the Restylane Silk will be needed. I would advise you to see a board certified plastic surgeon who is certified to use this product. Good luck!
Based on your photos, you do not appear to have small lips - you appear to have indentations on both sides of your cupid's bow of your upper lip. Your lower lip is a bit volume depleted by the corners.
Depending on your examination, Silikon-1000 may be considered to provide permanent augmentation in certain parts of your lips.
Hope this helps you.