If you do see a mech you like, you can always put a regulator in it (turn it into a VW/VV device).
These are called
"Kicks" or "Crowns", and range in price from around $25 - $50.
The real deals are by companies called Evolv (USA), and Artisan (Canada).
You can also find lower priced (but also less versatile/powerful) clones by companies like SmokTech, Sigeli, and Kamry.
Given one of these regulators, in addition to something like a Nemisis clone (a perfect flush fit with the KayFun)...you could get the combo for a similar price (maybe even less) to an APV.
The main things that you'd be missing by "Kicking" a mech are:
A screen showing the settings.
Built in Ohm meter.
Not as easy to adjust (if you go with a model that uses a pot adjustment, you'd have to open the mod to adjust the Kick's power setting...usually not a problem).
The things you'd gain by going this route:
Adjustable air flow built into the mod.
If you went with an Artisan Crown, you could trade some power for being able to adjust it without opening your mod. The Crown also has an Ohm meter (long and short beeps to tell you what it is).
The safety and regulation options included with other APVs.
Potentially more versatile (can take builds down to 0.5 Ohms) and powerful (up to 15w) if you go with a Genuine Evolv Kick 2.
A shorter, lighter, lower profile PV.
The option to take out the Kick if you ever want to experiment with a fully unregulated set-up.
The best regulated vape I've had to date can be seen below:
Kicked Brass Nemisis Clone

I took the top off to show how easy it is to get to the Kick 2's Pot (the blue square thing) in a Nemisis. In this mod I adjust the power by turning a little screw inside that pot.
And here's some other mods I have that either contain a Kick or Crown.
1. Saber Kicked Edition w/Crown 2.0 and 18650 battery, 2. K100 with Crown 2.0 and 18500 battery, 3. Nemisis w/Evolv Kick 2 and 18650 battery.

I chose a Crown for the Saber and K100 because I don't like having to fish it out to make adjustments. Also the Kick 2 won't work in the Saber. Notice how short the Nemisis is, even with a kicked 18650!