They’re super cheap and plentiful for parts plus nothing is rocket science on them making servicing cheap too.
As for insurance I had no problem with Carole Nash insuring my Monster, the ‘Cat plus my old P200e Vespa.
If yours don’t do multibike ask about mirroring your NCB across on another policy.
For those not familiar with mirroring there is a good explanation of it here (ignore that it’s on a quote site) but mentioning it may get you a better deal when insuring more than one bike.
https://www.quoterack.co.uk/No-Claims-Bonus.aspx