derekullo :
You could buy 5 - 1 gigabit connections and bond them together for an effective 5 gigabits of pure unadulterated speed, although for that price you might as well go for a 10 or 40 gigabit nic/router and the necessary fiber optic cabling.
Can't wait for 10 gigabit over copper.
link aggregation doesn't work that way, though. If you software bond 5 ports together, you can get 5 outgoing streams at 1Gb, but no one stream could do more than 1Gb. Plus, incoming traffic would be limited to just 1 NIC. If you use LACP, which requires a more expensive switch than 10G, while it would allow 5 1Gb streams incoming, you're still limited to 1Gb per stream in either direction. It's not "pure, unadulterated speed" in any case.
10Gb started with copper: the CX4 connector, which was limited to 10m cable lengths. Now, we can even use SFP+ cables, but the interaction between NICs and switches over those cables is iffy at best, plus cable lengths are limited to 3m for passive cables and 10m for active cables. We do now have 10Gbase-T, which allows 10G speeds over cat6a or cat7 cables at up to 100m, but they're power hungry.
10Gb still works best over optical, but that's not a bad thing. The cables are far more durable than they used to be, and not 10Gb SFP+ modules can be had for $20 and 3m cables for $11. The switches have even come down quite a bit. I've found switches with 2 10G ports available for as low as $200, and 4 ports for $400. I just got a 28 port switch with 4 of those ports being 10Gb SFP+ ports, the Dlink DGS-1510-28X, for $400. The SFP+ modules were $20 more each. It's not nearly as noisy as they claim, either. My system is noisier because of my Corsair H110GTX cooler.