After you 'BUY' your first BIG model - the costs are minimal and the benefits are enormous.
Let's do a comparison;
-Gas is cheaper than Nitro.
-Gas is cheaper than BIG Batteries and the Chargers.
-The Servos are more expensive - but they last longer.
-The Engines are more expensive - but they last longer.
-The Radios are the same.
-Tuning a Nitro engine can be a PAIN!
-Tuning a gas engine is EASY!
-Cleaning a Nitro plane can be a PAIN!
-Cleanng a Gas plane is EASY!
SPACE - it the big problem.
Space to store a big plane and the ease of transport to the field. (these are little problems)
You can REDUCE this problem by keeping to 30cc sized aircraft.
At the end of this chatter -
Life is short!
Enjoy it while you can!
Get the Plane that YOU WANT! 
and
NO! You are NOT crazy! 