To install a non encrypted analog commercial quality system using a free standing rack, MPEG2 DVBS rack mount receivers, a 1.2M dish, NTSC frequency agile modulators, a combiner and launch amplifier, plan on spending about $500 - $700 for the first channel and and $300 each additional channel. Local channel insertions would cost about the same if down converted to SD NTSC analog. You could even use a laptop with PowerPoint and a TV out card to create your own RV channel for your guests with local events calendar, weather forecast, etc. Maybe use a local Radio station as audio. This would guests a reason to connect your system even if they have other TV programming options.
The cost per channel could be lowered by using set top boxes for the satellite and the terrestrial receivers, but STBs are designed to have the channels frequently changed. They are not designed to sit on one channel 24/7. A STB left on a single channel 24/7 will usually start having decoding or lip sync issues. Guess you could address that by putting a timer on the system to shut all STBs off every evening for 30 seconds, but no reliable solution. Fixed channel modulators will also lower your initial cost, but then you are committed to placing a channel on a predetermined channel number and may have to replace the fixed channel modulator with another channel modulator if there is interference, either from electrical devices or new TV channels, FM radio stations, etc.
It is always a good idea to use commercial quality frequency agile modulators when combining multiple modulators. Consumer grade modulators usually don't work well as the frequencies start to interfere (herringbone or zigzag lines) with each other and overlap if the channels are located on adjacent channels. Great for a few channels and short distances, but not recommended for what you are proposing. BTW. I would love to sell you frequency agile modulators, but they have been a dime a dozen for used units on eBay in past years as more cable head ends transition away from analog NTSC to QAM.
Local terrestrial digital TV channels could simply be reinserted into the distribution, but that would provide a mix of digital and analog channels and require the modulators to be run on UHF/VHF channels instead of CATV frequencies. This type of system would need to be well constructed due to the potential signal leakage in and out! You would want to avoid using specific channels that could cause interference to local aviation frequencies and TV / FM radio broadcasters.
It would be least expensive to down convert the terrestrial digital off air channels to analog CATV frequencies. It would be very expensive if upconverting all satellite and local digital channels to QAM for distribution. Last I checked, a QAM modulator cost is around $800 - $900 per channel!
