Reke is worth more than MT's 8M per.
He's worth more than DeRozans 10M per.
He's probably worth more than Curry's 11M per, especially since Curry got that with lingering ankle issues and he still hasn't shown he can get past those problems, or is past them.
So you're probably looking at a Lawson type deal, minimum, at about 12M per. If he plays like he did last night for most of the season, he's worth more than that. Then you have to worry about teams like Dallas and Atlanta who will have a lot of cap space and might try to make an offer the Maloofs would be nervous with.
Not extending Reke could be either a good thing or a bad thing, time will tell. But I doubt we save money. I don't think we sign him for less than the Curry extension at 4/44, and we might have been able to if the FO had been more positive about Reke and more open to discussing an extension. There's a possibility Reke doesn't even want to resign here, and used the lack of extension talk to motivate him all summer to basically tryout for other teams. He wouldn't be the first player to do that. It's also possible he decline any and all extensions/offers and only signs the QO, which lets him leave the following summer. We just don't know how Reke's camp views the pretty public stance of "we're not willing to talk an extension with Reke" from our FO. It's an assumption that he's fine with that stance and will happily sign one next July. We just don't know. If his jumper proves to be more consistent all year, it might give Reke the confidence to just sign the QO and test the market the following summer as an UFA.