I am going to plead old age, sometimes it takes me a while to connect the dots. If you are not close to a beacon correction station, there is another option.  A 750, 500, 250, or 132 can accept external RTCM corrections.  A  stationary 132 Trimble receiver is capable of generating RTCM corrections.  When I checked about 6 months ago, that option was still available for about $1000.  Used Aggps 132's are going for about $500.  Add the same radios that you need for RTK and you now have your own very close beacon station.  It is not RTK, but you will not have nearly as much money in it.