I found a helpful website that has information on all of the keloid removal options with each's level of effectiveness. The information they list to read the article is Treatment of keloids and hypertrophic scars Mutalik S - Indian J Dermatol Venereol Leprol
I hope this helps. While it does not specifically mention costs, you could use the article to determine which method is most effective and then talk to your doctor and insurance company about costs.
More information about the article is below:
Mutalik S. Treatment of keloids and hypertrophic scars. Indian J Dermatol Venereol Leprol [serial online] 2005 [cited 2008 Dec 30];71:3-8.
Take care. Hang in there! There are people who understand your pain.