Hi Colin, I'm a newbie too and only 49 years young. Registered today for advice on the first bike I bought less than a year ago.... went for a cheapie which has ended up a money pit, and then bought a 250 gas gas and I am totally addicted and so pleased with my mid life crissis!
Looking back on the last 10 months I should have spent £1500 on a 250 2 stroke... that's only my opinion after 10 months and I'm more than happy with the gas gas but £1500-£2000 gets you a nice bike... good luck