Difficult one to answer as the ground is a little unusual. If you live anywhere nearby I'd suggest visiting and looking around.
Most expensive season tickets cover the covered top tier. Usually sells out to season ticket holders so you may or may not be able to buy a ticket. View from the front couple of rows reputedly part obstructed by a handrail. The area is often home to a drum.
Mid price season ticket - uncovered lower tier seating in the stand. I'm dubious about this area as people often walk past and it is exposed to rain etc.
Cheapest ticket - uncovered seating one end, covered "temporary seating" the other end and flat standing elsewhere. Be aware that a fair chunk of the side opposite the stand is effectively no go for spectators due to match control buildings, coaching staff standing up and blocking the view etc.
Personally I buy general admission and just mooch round, where I go depends on the flow of the game.
Welcome to the slightly strange world of southern RL. There may not be many of us but we do love the sport and if you accept the limitations Trailfinders can be a pleasant enough place to crash out and watch some RL on a nice day.