Myself, I'd never go with a gay-hostile company, no matter how much I saved. I'd go with a well-known gay-friendly company if the costs were about equivalent. But I'd probably go with a company not known to be friendly or hostile over a famously friendly one for a $40 saving.

But, do you have a partner who's coming with you? If one company adds domestic partners automatically and another charges you extra for adding them, that may change the price difference. I'm pretty sure that at all corporate-owned locations and most franchised locations, Avis considers domestic partners to be automatically authorized drivers just like opposite-sex spouses.