Do you have a job yet?
I ask b/c beardies ARE expensive pets. It will cost a few hundred for the initial fee of a proper set-up (the large tank itself, good lighting, digital thermometers, accessories, etc.)
You need to find a good reptile vet- NOT a typical cat & dog vet...; you need a vet that specifically studied reptiles b/c they need certain care, and some medications that an unknowledgeable vet may give are lethal. Beardies (and reptiles in general) are prone to parasites so need regular fecal checks, and they need medicine if they get parasites. Ridley's typical vet visit costs over $100 just for the office visit and handing them a bag of poop.
They eat ALOT. As babies you'll go through possibly 50 or more crickets a day, and they need to be gutloaded and dusted with proper vitamin supplements. And they need specific veggies.
So make sure you DO research alot before convincing your mom to let you get one.
It took me 27 years to get a beardie lol.
But yes, it was a costly pet to get into, and he has had parasites even though I give him the absolute best care so he has given me a few vet bills. But I love him immensely and wouldnt trade him for the universe.
BUT if I was young and didn't have a job where I could afford his care, I could never afford a reptile b/c my parents would have to be responsible for all the costs.
A reptile isn't a pet you should beg for without really knowing what you are getting into. When my mom finally agreed to a reptile in the house, I researched beardies for around 6+ months and got everything set-up ahead of time.
And now she is in absolute love with my little dragon