That's actually quite a nice looking collection and very reasonably priced.
I have seen a lot worse for a lot more.
Don't get me wrong; I have about 100 PMC prepainted buildings myself (mainly framework houses bought at £9.99-£19.99 let alone other PMC stuff...) but this is a typical something one can do in an afternoon (or a day at the most, painted and all) if you set up a production line using cork and some urethane items from the craft shop.
I'm currently building up for Nam games (28mm) and needed a village (hooches). Based on Matakishi's idea, I have built a pilot model, but a bit more elaborated:


I never worked with cork before (it's great to cut, thanks Mata!), so concept, building and painting took me about 2.5 hours. I'm confident I can make a village in a day (which - in resin - would have set me back £ 100 without shipping, that's a lot of figures). I made this Arab village with lift-off roofs in one day ( made from that white architect's stuff 5 years ago):

It still needs a repaint (it's too light, so one of these days I'll let it pass under a Warpainter spraycan). An option worth considering. I haven't done this for budget reasons (I have also little enough hobby time as it is), but some things just can be done cheaper by oneself.
Rudi