Ok, so the harsh reality of being on the 'other side' of 50 has hit. Along with the occasional dodgy back, and the knees that have not much cartilage left. Rural life allows access to long level dirt roads along our valley floor, with the occasional hill.
I want to improve my fitness, so gentle biking seems appealing.
I have not ridden a bike for many a year, but do other stuff to keep in 'reasonable' shape.
What should I look to buy, & what should I expect to spend? Don't really want to spend big bucks.
for dirt roads a mountain bike (MTB), they have front suspension and wider tyres and cool advantages like disc brakes over a common road bike, for a new bike you would typically find good offers in the 700 to 1K dollars range, on top of that you need to buy a helmet, a basic patch repair kit, a pump. Cycling apparel is not compulsory but it is nice to have,
Or, you could split the difference between a mountain bike, and a road bike, and get a cyclocross bike. It all depends on the terrain. 'Cross bikes don't have suspension forks, but they usually have 32 mm wide tires with aggressive tread. Some also come with disc brakes. However, if these dirt roads have a lot of bumps, or obstructions like rocks, stumps, and other hazards, a MTB with the suspension fork would be the better choice. You definitely don't want a standard road bike, with 23 or 25 mm tires, for dirt roads. Skinny tires and loose gravel are a bad mix.