Licensing dilemma (age 23 UK)

Hey guys, I've been wanting to get licensed for a while now. I'm a complete rookie who has yet to even do the CBT. Here's the thing, the A1 and A2 tests look like an absolute pain to get through. They're expensive and very easy to fail for an inexperienced rider. I'm 23 years old right now, and I'm very tempted to train up to my A2. However, I've realised that obtaining your unrestricted licence would mean redoing A1 and A2 all over again in just a years time. That seemed incredibly expensive when I could just wait to age 24 next year and do direct access. Does it make more sense to pass my theory and CBT, buying a 125 right now? Or should I power through to get my A2 so that I can buy the bike I want, having it restricted. I'm also considering things like the horrific insurance costs for a new rider and how best I can mitigate that dependingon my path. Cheers!