Welcome Zulu, good choice I reckon.
From recent experience helping my mate's lad buy his first bike, the dealers are telling me they're flat-out. The story I keep hearing is that BoJo's call to avoid public transport has created a spike in sales, leading to low stock of new bikes, spiked second hand prices and general demand for mid to entry level bikes outstripping supply.
We ended up going 130 miles to find a dealer who held the bike he wanted (a UM Renegade Scrambler 125). The next nearest was over 200 miles away.
I certainly got the impression from a recent search for second hand 125's that prices were silly, about £500 above where they ought to be. If you can get a new or recently used bike for a decent price I'd advise you to go for it. Of course, summer is an expensive time to buy but this year seems particularly fruity.
All the best.