Jason, I'm afraid that what you're proposing won't work. Ethernet networks are governed by the IEEE 802.3 standard and it appears that you are using a 100Base-T flavour 100mbps over Cat 5.0 cables. There's one of two things that you can do to resolve your problem but NONE are inexpensive:
1 the only cable you can install that can support signals over 800feet (that's about 250 metres!) is fiber-optic. Multi-mode fiber supports distances up to 300 metres; single mode fibre distances up to 40 kilometers (that's 25 miles!). You will also probably need to change your existing hub to one that can support a fiber-optic link though (if you're upgrading you might as well opt for a switch). Of course you'll need ANOTHER switch to route the data packets over the link at your remote site. So here's the rub: (a) change your existing hub (unless it already supports a fiber link) (b) buy a switch for your remote site (c) connect them by means of fiber-optic cable. One advantage to this is that you're well on your way to upgrade to Gigabit ethernet - that's 10x your current speed!
2 The Ethernet standard also allows for signals to pass through cable television networks (10Broad-36) and if you have a cable television provider in your area who is also into data network services you COULD pay for a virtual private network service. This would involve paying a monthly fee, and getting a cable modem for either end of your sites (also provided by the cable TV guys). Not cheap either but I'm afraid there's no simple formula that would work in this case.
You might find this site useful for a BRIEF but good description of terms we are talking about:
http://www.webopedia.com/TERM/E/Ethernet.html
You may find out the meaning of other terms using this site.