"Generic" cue you say? If by that you mean "off brand" then I don't really know that many. Some of the lower end of more known brands are surprisingly good. I don't know if I've ever tried a cue cheaper than 100 bucks that was really nice hitting. Those cheap cues usually vibrate too much and have bad, soft shaftwood. They will play ok, though. I have no trouble recommending Players HXT or Cuetec r360 for their playing qualities but to me they feel really cheap. If the feel matters to you, that should be taken into account.
I tried an Elite cue that had some kind of knockoff Radial joint that I thought hit ok. I belive it was just over 100 dollars, may just have been a golden example, though. A relatively inexpensive cue is the McDermott low end G-series. Some of those cues feel like expensive ones. All the cheap cues I've tried (and I've tried most of the common brands) hit like cheap hunks of sh..Once you've tried as many as I have you instantly recognize the cheapness, especially with metal jointed cues. Apparently they are harder to do properly? The only cues that sometimes surprise me a little are "sneaky" style cues. That would be the best bet, I think, for a cheap cue that hits like an expensive one. Doesn't have to be a custom "conversion" either. Just any full splice, wooden jointed cue or even just a wooden jointed cue.. The only factor that will make or break it is wood quality, and you can get lucky sometimes.
I tried the import McDermott cues. Bought a "Lucky" cue for myself. All the glue joints failed. The ferrule fell off, the joint collar fell off and the internal glueing failed so the cue got a nasty click...You get what you pay for, sometimes much less! That was 40 dollars wasted! The Star cue I tried hit like a 2 by 4. No feel what so ever, stiff but not in a good way. Couldn't run 3 balls with that cue if my life depended on it. I don't like Vikings Valhalla line either. Low end "regular" Vikings are ok, though.
Lucasi cues are quite expensive now, but when they used to be cheap they were pretty good value for money. Now they are as expensive as Mezz cues! No question which way you should go if those two are your choice.
I bought some cues from the Phillipines...They were not exactly laser straight but a couple of those cues were great hitting! It was hit-or-miss with those cues, though.