Yes, silicone is extremely safe, and generally the material of choice (along with stainless steel) for industries such as pharmaceutical, medical, dairy, and, of course, brewing. But regular silicone tubing can't handle the pressure from household plumbing (though a typical brewery pump like a March 809 or Chugger pump is fine). If you're careful enough to make sure the path of the water is unimpeded at all times (ie you don't let pressure build up inside it and burst like a balloon), you can get away with it.
If it's just tap water, though, braided vinyl should cost about the same as the (unbraided) silicone tubing, and is also safe under such conditions. I'd recommend going with the braided vinyl rather than chancing it with remembering to keep all the necessary valves open every single time... ESPECIALLY if it's only going to be from the cold water supply.
Stick with silicone for liquid that is very hot, or that is acidic (like wort/beer) though, especially when it's hot.
If you let me know specifically what you'll be running through each hose you'll need, and the temp range you expect (particularly the upper end of that range), I can give you much more specific recommendations.
I hear you, though... $7/foot definitely isn't cheap. Anybody that wants to incorporate braided silicone (Silbraid) into their brewery really needs to plan things out to maximize efficiency, minimize the necessary length of Silbraid tubing as much as possible, and use unbraided hose wherever possible. Many home breweries can easily use more than 50 (even 100+) feet of hose, so not putting some thought into how your hoses are set up and constructed can cost people a small fortune.
Thanks for the info. I have 20' so far just to get started. Replacing the RV hose to the shop is going to hurt...that's 50' maybe 40psi and never over 65* unless it bakes in the sun during our two months of summer.