I am going to say, you are not really going to find that. But if you want something cheaper, it won't really be like Spinart, but it will be pretty much what you are looking for, keep the Hurricane 3 and boost it more. You could also use Skyline 3 and boost it extra.
Addidas P7 is not like Spinart. Spinart's rubber is not as bouncy and P7's topsheet is not as tacky.
Spinart is a spring sponge like Tenergy but harder and so, less bouncy and it has less of that real jump that Tenergy has. The topsheet is also similar to the Tenergy topsheet but a little more tacky. I guess one other thing you could try is Xiom Omega IV Asia. That is the Omega IV with the hardest sponge. It will also not play like Spinart but it might be something you would like. The Omega IV topsheet grabs the ball really hard and the sponge on the Asia may be similar enough. That rubber may get more spin that Spinart and it may be a little faster. I am not sure. But the price is not that much less.
That is why I say stick with the Hurricane 3 and just get commercial and boost it like crazy. H3 commercial is about $20.00 USD. That is the only thing that is going to be that good and that much less expensive.