Alan I think that is missing the point with the Heng Long stuff. In their most basic of forms they are toys and were originally, and indeed still are, sold as such. They are not sold as hobby model kits There is still a market for them as toys and there are many quite happy to buy the most basic of models to play with out of the box. In this form they are pretty cheap and entertain a lot of kids (and adults!).
However the aftermarket stuff has developed at quite a pace as a result of incredible demand from modellers who see a way of building a very decent scale model from one of these toys. The best can easily compare with the 600.00 pound plus offerrings from
Tamiya so in that respect can be seen as very cost effective. I personally see them as a great opportunity to create a very realistic RC model tank at a very reasonable price. You can buy as much aftermarket stuff as you want or put in as much scratchbuilding as you want, the choice is yours. You can also do nothing more than a complete repaint, which can also achieve some fairly impressive results and give a lot of modelling satisfaction and you can pick up the basic toy for around 50.00 pounds. Most people wouldn't think that too bad for a good scale 1/16th replica. The guy that built the one I showed earlier in this thread digs out plastic around the turret edges, fills it with putty and presses a tool into it to create the heavy welding so well known on this construction so there really are plenty of modeling opportunities.
As with everything it is each to their own but it is not fair to critisise Heng Long products for requiring aftermarket bits to make them into a model when they are not sold as such.