Not sure I agree with anything you've said there Lofty. Admittedly, SMKs aren't finished to an exactly consistent standard, but the likes of the XS19, XS20 and XS38 are all solid rifles. These are rifles genuine branded SMK rifles, built by BAM, and these all cost £150 and upwards. The cheaper end of the SMK range is built by Westlake, and certainly not worth even looking at. The BAM build SMKs can be turned into very nice rifles with a little tune up.
That said, this still doesn't fall within the OPs budget of £100. Nivek65, as Buster said, you'll have to closer top double that mon