If you look on the for sale section of RYCAs website 4-6k seems about the going price. There are a few as much as 8k but there's more invested than just a RYCA kit.

Having said that I bought my RR bobber kitted RYCA build in rideable condition for 3k of craigslist locally. It needed some mechanical work (cam chain tensioner) and tuning but it all in all was a solid bike that the owner either didn't know how easy the fix was or just didn't want the hassle. At the time I bought mine there was a like RYCA bobber build for 3600 that had the wiseco 97s in it. Only reason I opted away from that was the owner was young and I worried with the performance upgrades it had been beat on more than normal. There's a CS-1 build on CL right now for 4k that seems clean and with wife's approval I may swing out to take a look and possibly purchase. Would be nice to have a choice between a cruise PCH bike and a hit the canyon roads bike that share the same power characteristics.