Hey, You Can Buy the TM35 Flamethrower in the Game Corner for 4000 coins, which would cost you approx. 80000 dollars, each 500 coins is 10000 dollars, you can also get ice beam, psychic, double team, and one other i can't remember... I hope this Helps =D
From Kadin
u can buy one at the game corner in celadon city.
You can "purchase" a flamethrower TM in the game corner coin-tradey place.
You can find the TM Flamethrower in the Game Corner in Goldenrod city for 10,000 prize coins.
I
It does not learns flamethrower you have to give it the TM flamethrower it is before enterna city you have to surf and a factory comes and you walk and walk until you find the TM flamethrower.
TM35 (Flamethrower) is located in the Abundant Shrine.
at the game corner
You can trade a Pokemon that is holding the TM from diamond to soulsilver or pearl or platinum or you can migrate a Pokemon holding the TM from ruby, sapphire or emerald or firered or leafgreen.
at the mauville game corner
Flamethrower is TM 35 and you can buy it in the celadon game corner
TM 35. You can get it from Route 28, or the Goldenrod Gaming Corner
rapidash learns flamethrower if you get the TM flamethrower and teach it
You can get TM 25 (Flamethrower) at the Mauville Game Corner for 4000 coins.