I use a generic 2.5% cream by Fougera that my pharmacy charges $12 for. I found a 2% version online for as low as $3.50 a bottle with a quick search. You can't bath in this stuff, and there are restrictions with the patches as well.
There's also a 5% version, so discuss it with your doc and pharmacist.

I haven't tried low dose naltrexone, but it's something worth researching, as well.