I share your pain anabol, I to am going bald from injecting tren hex like a fucking idiot (as in, knowing it will make me bald as a coot).
I consider the price worth it if it means I can maintain strength while cutting down.
However, there are far more steroid friendly hair stacks if you're determined to keep your hair.
For instance, deca shouldn't cause much hair loss at all and seems to me that would suit your goals (as it converts to a much weaker androgen than DHT). You could run deca with as little as 250mg test. So why not run those steroids instead of just test, which will likely make you bald even with finasteride past 500mg a week?
Further more deca increases collagen synthesis in the tendons, whereas most other steroids decrease it (the doses related to a steroid cycle of testosterone can decrease collagen synthesis by up to 80%). THe point being, long term use of test predisposes an individual to muscles tears and general joint fuck-uppery by increasing muscular strength and decreasing joint strength. So everyone should run some deca with their steroids.