I have amassed a collection of lenses...both good and bad.
Both my Canon lenses (80-200mm, 28-80mm) are plastic mount ones. The 80-200mm costed under £60, the 28-80 costed £35. The autofocus is exceptionally fast although the 80-200 doesn't even have USM!
I also have a 35-105mm, 70-210mm and 50mm Minolta lenses. They're metal, built like tanks and weigh a fair bit, like my metal Minolta 7000 body. All my lenses, apart from the 70-210mm and of course the 50mm prime have one f number throughout. The rest don't.
It's just a good thing I'm looking to get a refund on the 70-200 Canon lens and buying that 70-300mm Sigma APO job
I will be selling my 28-80 USM as well as my EOS 300 and using the petty amount of cash I'll get to put towards a 30V or maybe go digital
SO yeah, you haven't really gone wrong there, not for £100!