I was lucky to get my latest Mirena inserted when I still had COBRA.

It is expensive without insurance, true, but, remember, it is a front-loaded one-time investment. Mirena lasts for 5-7 years (check) so you need to calculate the monthly cost first, and then you just might be pleasantly surprised. Especially since you will reap the benefits of not being moody.

Also, PP might give you a sliding scale:

IUD Birth Control - Mirena IUD - ParaGard IUD