On the entry level end of the spectrum, the Crosman 2240 and the SPA CP1-M (marketed as the Mrodair Targetmaster, Diana Chaser, and others) are the ones that come to mind. I have both and they have their pros and cons but they both represent good values.
Be mindful that all the ones on the low end are wasteful of CO2 so they will benefit greatly from some tuning. At the very least, adjust hammer spring length or preload, but preferably add some sort of anti-bounce feature like an SSG or bstaley O-ring buffer. For example, my CP1-M went from about 25 shots per cartridge to over 50 by adding an O-ring buffer, at a negligible tradeoff in velocity.
A byproduct of being a CO2 hog is also that it makes the velocity particularly sensitive to minor changes in temperature, so that’s another good reason to do some tuning. Granted if the distances will be short, say for 10m practice, I doubt it would be noticeable but if you’re wanting to use it for 20 yards or more, the trajectory variation would be obvious.
Between these two models, in my opinion the CP1-M is the better value (all wood and metal, better trigger, single-shot tray or magazine) while the 2240 has better manufacturer support and parts availability.