Hello Reivax,
The best medium tele zoom I've tried in the range you're looking for is the SMC Pentax FA 100-300mm f/4.7-5.8, (only the silver version). I see these go regularly on eBay for around $100.00.
Mine works fine for a budget zoom, fairly sharp, decent IQ and fast (but noisy) AF in good light.
The review here;
SMC Pentax-FA 100-300mm F4.7-5.8 Reviews - FA Zoom Lenses - Pentax Lens Reviews & Lens Database
It's rated several points higher than any of the other similar-range zooms, @ 8.87.
It was my go-to medium-tele zoom until I scored a used Tokina AT-X 80-200mm f/2.8.
The FA is light (almost too light), has a plastic bayonet which has never given me any problem, and does hunt a bit in low light, because of the slow maximum aperture. But with ISO 400 (or higher) film you should be OK.
Just make sure you get the silver one!
Ron