With the 2 knives the OP mentions, if you want to get into it in an affordable way that lets you maintain the good factory edges that will be there on those knives already, I agree, Sharpmaker is a good place to start without spending an arm and a leg. If you have the same Cold Steel Recon that I have, with the newer CTS-XHP steel, that's a pretty hard "super steel", and if you want to do any serious sharpening over time, it'll go REALLY slow on the Sharpmaker, unless you upgrade to the add-on/extra diamond rods, or the new CBN rods. And even with those, speaking from first-hand experience, don't even think about trying to do any serious re-profiling of your bevel on Sharpmaker, it just takes forever and will drive you nuts. For re-profiling, as somebody said, get a bench stone such as Baryonyx American Mutt, I own that and for $7.50, that thing is fantastic for profiling. However, the good news is that with your Benchmade and Cold Steel Recon, if they're in new or near-new condition, they already have good primary and secondary bevels, so you don't need to profile. Cold Steel for example puts a very high quality shaving sharp edge on the Recon from the factory, so you're starting in a great place and just need to maintain it. Sharpmaker is great for that, should be able to maintain with the included fine ceramics, or later, you can upgrade it to get the ultra-fine ceramics, or the CBN rods if the hard CTS-XHP is making the cutting go too slowly on the ceramic rods.
Over time if you want to get into fancier sharpening and have more control over the angles, more refinement, etc., this is just me personally, but I'd avoid the more expensive guided sharpeners, and get DMT diamond bench stones, 8" or larger. You can get these in just a few grits, and you'll be able to do everything you need to do.