I wouldn't recommend the use of anything more than 200 feet of buried cable, simply because of RF attenuation. Most carrier frequencies for high speed data over cable are around 600+ mHz, which (depending on cable gauge) would drop off to near nothing over the distance being described. Simple house amplifiers may work to keep the signal high enough, but the gain on most amps would likely result in a terrible signal to noise ratio and as a result: spotty connection. The best option may be to dig the trench yourself (DitchWitch rental for the afternoon), lay the conduit (ask for the specs from the cable provider), and contact the cable company for the remainder. I can't imagine it would be 10K for simply the conduit push and cable. Make sure to follow power and phone to your property (easements) and GET LOCATES! You don't want to be the asshole who strikes power...