GT I read it was £250,000. In my opinion though they are worth every penny and my daughter is a million times better than any material possessions money could buy. I completely understand what you are saying, but it is my opinion any money (be that in voucher form or whatever) given to M is intended for her, so even if we spend the vouchers the equivalent and any cash is put into her savings account for her future or any big essentials she may need in the short term (ie, carseats etc, and if these are then sold on in the future I will put that money back into her account).
I had an amazing upbringing but money was always tight being from a single parent family with a selfish arsehole father who didn't contribute a penny towards us. My mum saved as much as she could for us, putting away money and values of vouchers that were gifted to us if we didn't need anything at the time. As such she was able to present us with a healthy trust fund on our 18ths. It made a huge difference as a student and meant I could come out of university with minimum debt. Every penny really did make a difference in our family and my mum would far too often go without so we didn't. I have a massive amount of respect for her because of it.
That's just my opinion though. If you want to spend the money on yourself then go ahead, as with all aspects of parenting it very much depends on what works for you.