Let's see -- 10 times a month is 120 round trips a year, with about 2 hours or a bit more each round trip, or some 240-300 hours a year, depending on speed. Divide that $25K/year by 240-300 hours/year, and that's an operating cost of $80-100/hour. The turbocharged, high performance, pressurized, retractables about which you've been talking cost at least twice, maybe three times that per hour in operating costs.
For an operating budget of $80-100 per hour over 240 hours a year, with $250K to spend on purchase, you're looking at something in the 4-seat, fixed-gear 180-200HP class, like a new or nearly-new Cirrus SR20, Diamond DA40, Piper Archer, or Cessna 172SP. For trip lengths of 160nm, those will give you nearly the same times door-to-door as the fire-breathers about which you have been talking, but within the operating budget you desire. I'd suggest you try to fly the all and see which one makes you happiest. In addition, there are legacy aircraft which would fill the same bill but with less than half the initial investment include the legacy Cessna 172/177, PA28-161/181, Grumman Cheetah/Tiger, and Beech Sundowner -- decide if you want to save some investment money by going that route.