The design might be the "easy" part, these are 6 tons of one off highly specialized components with a huge lead time. Each component is custom and built for order by a contractor the lead time on some of them can be years simply because there aren't that many companies that design and build space systems.
That combined with the fact that they need to go to each subcontractor and ask them to bid again after Spacecom finds a way to finance it (there is no way the insurance payout is anywhere near the actual cost of the satellite) would probably mean that the time it takes to build a new one isn't that different than it was to build the original.
Think of it like this if you total your McLaren P1-GTR there isn't an easy way to get a new one ;)
I'm 15 years removed from the TV biz, but I vaguely remember 'birds' costing like $350m to launch, something like $200m + for the hardware, then $150m for launch fees and misc pre-launch insurances. In some cases, I want to say they insured them before taking possession of them, like if some guy at Lockheed has a bad day and drops a wrench on exactly the wrong part, you're looking at a substantial delay which could substantially impact business. Companies would talk up these satellites to investors for years before they launched, hard to imagine them not being completely insured up in to space. Then there was launch insurance and I think it included operations in many cases, TV birds had a lifetime of like 7 years and the operational insurance paid out if they had a certain amount of failure before the lifetime was up, transponders die and they need to spend fuel periodically to keep them in place when the fuel is gone the bird is done. I want to say the launch and ops insurances were like another $100m to $150m. All told you were in for half a billion to get in in to place and that's not including the lease on the slot of sky... I'm pretty sure Echostar was involved in some lawsuits about it and there are probably some public details that came out of that; maybe they wanted to claim more damages than the insurer wanted to cover or something like that and then no insurers wanted to sell them operational insurance.
It's not cheap but if that's your business you absolutely insure it. It's not cheap though. Would investors let you get away not insuring one? Rockets not making it in to space isn't uncommon.
Think of it like this if you total your McLaren P1-GTR there isn't an easy way to get a new one ;)