IHS is a lot of money, especially if you have family - no doubt about it.
Unfortunately there is just no way to apply for Global Talent (in fact - any visa) without paying IHS again. Please also bear in mimind that if you get tier 2 visa for one year, than apply for Global Talent endorsement unsuccessfully you will need to apply for tier 2 once more and pay visa fees which are extremely high even without IHS
I know at least about several people who managed to get a refund.
There’s absolutely no guarantee whatsoever that you will get Global Talent visa as the bar is extremely high and it is only getting higher. So I would not be worried about the IHS now.
Also, I would think twice if joining a company which can’t cover the cost of the visa is a good idea at all. Since your visa would be chained to that company and will be revoked if you are laid off, company goes out of business or simply can’t afford sponsorship license anymore.
Paying for a visa is a minimum relocation compensation a decent company would offer.