I think I got a good deck that fits your criteria - My 7 year old son runs it and he can hang at league challenges and such...and very budget friendly
Pokemon - 13
4 Charmander TEU
1 Charmeleon TEU
4 Charizard TEU
4 Oricorio Celestial Storm
Trainers - 34
4 Rare Candy
4 Pokegear 3.0
4 Cynthia
4 Pokemon Communication
4 Welder
4 Fire Crystal
1 Lillie
1 Greens Exploration
4 Switches
1 Power Plant
1 Heat Factory Prism
2 Energy Recycle System
Energy
13 Fire Energy
This deck is probably less that $40 - nothing terribly difficult to find. I think the Charizard's and the Pokegears go for about $2 a piece
I have seen similar versions to this deck with Volcanian instead of Oricorio - Volcanian's go for about $7 a piece. Honestly, even without the price of volcanian being a deterrent, I am a huge fan or Oricorio in this deck - extremely distruptive, low energy cost and gives you some gusting ability. Plus, you tend to catch people off guard as no one really sees that card.
[R] Captivating Salsa
Switch 1 of your opponent's Benched Pokémon with their Active Pokémon. The new Active Pokémon is now Burned and Confused.