I would say buy yhe best quality you can afford. many of us started out in the under $800 range and the upgrade soon after wishing we bought the better one the first time.
Second I would say I wouldn't be afaid to buy used if you a careful the are a lot of hardly used high quality guns to be had for great prices. Airgunners are a strange bunch, me included. We tend to fall for the latest and greatest new gun out there and in a couple of months sell in at a loss to get the next latest and greatest leaving a lot of slightly use high dollar guns in the classifieds begging for a new home. I prefer a used Brocock or Huben K1. You can pick up some Brococks for under $1000. use and they are excellent quality guns for hunting and really hold their value if you by used. A used Huben K1 can be had for around $1000 ifyou look for it. The Huben has plenty of power and accuracy for 100+ shots. And it is semi auto which might be nice for the prairie dogs. Hope this helps.